WorldWideScience

Sample records for perennial prairie grasses

  1. Perennial Grass Bioenergy Cropping on Wet Marginal Land

    NARCIS (Netherlands)

    Das, Srabani; Teuffer, Karin; Stoof, Cathelijne R.; Walter, Michael F.; Walter, M.T.; Steenhuis, Tammo S.; Richards, Brian K.

    2018-01-01

    The control of soil moisture, vegetation type, and prior land use on soil health parameters of perennial grass cropping systems on marginal lands is not well known. A fallow wetness-prone marginal site in New York (USA) was converted to perennial grass bioenergy feedstock production. Quadruplicate

  2. Defoliation effects of perennial grasses – continuing confusion | DL ...

    African Journals Online (AJOL)

    Although an adequate knowledge of growth patterns and defoliation effects in perennial grasses is a prerequisite for the rational use of veld and pastures for animal production, our knowledge of this subject is far from adequate. The results of various physiological and clipping studies on tropical and sub-tropical grasses are ...

  3. Flora and fauna associated with prairie dog colonies and adjacent ungrazed mixed-grass prairie in western South Dakota

    Science.gov (United States)

    William Agnew; Daniel W. Uresk; Richard M. Hansen

    1986-01-01

    Vegetation, small rodents, and birds were sampled during the growing seasons of 2 years on prairie dog (Cynomys ludovicianus) colonies and adjacent mixed-grass prairie in western South Dakota. Prairie dog grazing decreased mulch cover, maximum height of vegetation, plant species richness, and tended to decrease live plant canopy cover compared to...

  4. State of the prairies of marine grasses

    International Nuclear Information System (INIS)

    Barrios, Lina M; Gomez, Diana I

    2002-01-01

    At the end of the year 2000, INVEMAR gave beginning to the project Distribution, it structures and classification of the prairies of marine flowering in the Colombian Caribbean, guided to characterize ecological and environmentally the ecosystems in this Colombian sector, particularly as for its distribution, extension, structures, associate biota and intervention degree. The above-mentioned like answer to the lack of information that was presented to the date in almost all the levels (line bases and ecology) for this ecosystem, required to implement monitoring programs and to adopt conservation strategies for the same one. The information that is presented is based primarily on the results obtained during the execution of the project in mention. An diagnostic is done, a characterization of the prairies, epiphytes covering, associate fauna and it structures of the prairies

  5. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies

    Science.gov (United States)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  6. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies.

    Science.gov (United States)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  7. Ionomics: Genes and QTLs controlling heavy metal uptake in perennial grasses grown on phytoxic soil

    Science.gov (United States)

    Perennial grasses occupy diverse soils throughout the world, including many sites contaminated with heavy metals. Uncovering the genetic architecture of QTLs controlling mineral homoeostasis is critical for understanding the biochemical pathways that determine the elemental profiles of perennial pl...

  8. The perennial ryegrass GenomeZipper: targeted use of genome resources for comparative grass genomics.

    Science.gov (United States)

    Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F X; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

    2013-02-01

    Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species.

  9. Established native perennial grasses out-compete an invasive annual grass regardless of soil water and nutrient availability

    Science.gov (United States)

    Christopher M. McGlone; Carolyn Hull Sieg; Thomas E. Kolb; Ty Nietupsky

    2012-01-01

    Competition and resource availability influence invasions into native perennial grasslands by nonnative annual grasses such as Bromus tectorum. In two greenhouse experiments we examined the influence of competition, water availability, and elevated nitrogen (N) and phosphorus (P) availability on growth and reproduction of the invasive annual grass B. tectorum and two...

  10. Root proliferation in native perennial grasses of arid Patagonia, Argentina

    Institute of Scientific and Technical Information of China (English)

    Yanina A. TORRES; Mara M. MUJICA; Sandra S. BAIONI; Jos ENTO; Mara N. FIORETTI; Guillermo TUCAT; Carlos A. BUSSO; Oscar A. MONTENEGRO; Leticia ITHURRART; Hugo D. GIORGETTI; Gustavo RODRGUEZ; Diego BENTIVEGNA; Roberto E. BREVEDAN; Osvaldo A. FERNNDEZ

    2014-01-01

    Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that (1) defoliation reduce net primary productivity, and root length density and weight in the native species, and (2) root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species (i.e., Aristida spegazzinii, A. subulata and Sporobolus cryptandrus). Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season (2008-2009), cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid-and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length den-sity and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.

  11. Optimal prescribed burn frequency to manage foundation California perennial grass species and enhance native flora

    Science.gov (United States)

    Grasslands can be diverse assemblages of grasses and forbs but not much is known how perennial grass species management affects native plant diversity except for in a few instances. We studied the use of late spring prescribed burns over a span of eleven years on experimental plots in which the pere...

  12. The Perennial Ryegrass GenomeZipper – Targeted Use of Genome Resources for Comparative Grass Genomics

    DEFF Research Database (Denmark)

    Pfeiffer, Matthias; Martis, Mihaela; Asp, Torben

    2013-01-01

    (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold......Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass...... to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous...

  13. COMPARISON OF THE POPULATIONS OF COMMON WOOD-NYMPH BUTTERFLIES IN BURNED PRAIRIE, UNBURNED PRAIRIE AND OLD FIELD GRASSES

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, M.; Walton, R.

    2007-01-01

    Common wood-nymph butterfl ies are found throughout the United States and Canada. However, not much is known about how they overwinter or their preferences for particular grasses and habitats. In this study, the impact of prairie management plans on the abundance of the wood-nymph population was assessed, as well as the preference of these butterfl ies for areas with native or non-native grasses. The abundance of common wood-nymph butterfl ies was determined using Pollard walks; more common wood-nymph butterfl ies were found in the European grasses than were found in the burned and unburned prairie sites. The majority of the vegetation at each of the three sites was identifi ed and documented. Using a 1 X 3 ANOVA analysis, it was determined there were signifi cantly more butterfl ies in the European grasses than in the burned and unburned prairie sites (p < 0.0005). There was no signifi cant difference between the burned and unburned treatments of the prairie on the common wood-nymph population. A multiple variable linear regression model described the effect of temperature and wind speed on the number of observed common wood-nymph butterfl ies per hour (p = 0.026). These preliminary results need to be supplemented with future studies. Quadrat analysis of the vegetation from all three sites should be done to search for a correlation between common wood-nymph butterfl y abundance per hour and the specifi c types or quantity of vegetation at each site. The effect of vegetation height and density on the observer’s visual fi eld should also be assessed.

  14. No positive feedback between fire and a nonnative perennial grass

    Science.gov (United States)

    Erika L. Geiger; Guy R. McPherson

    2005-01-01

    Semi-desert grasslands flank the “Sky Island” mountains in southern Arizona and Northern Mexico. Many of these grasslands are dominated by nonnative grasses, which potentially alter native biotic communities. One specific concern is the potential for a predicted feedback between nonnative grasses and fire. In a large-scale experiment in southern Arizona we investigated...

  15. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Science.gov (United States)

    Talukder, Shyamal K.; Saha, Malay C.

    2017-01-01

    Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS) are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs). Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder. PMID:28798766

  16. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Shyamal K. Talukder

    2017-07-01

    Full Text Available Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs. Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder.

  17. Returning succession to downy brome dominated rangelands: roadblocks to perennial grass establishment

    Science.gov (United States)

    The most common cause of successional retrogression in the Great Basin is wildfires fueled by downy brome (Bromus tectorum). Downy brome invasion has reduced fire intervals from an estimated 60-100 years down to 5-10 years. Our previous research found that establishment of long-lived perennial grass...

  18. Changes of biomass in some perennial grass species. | M.C. ...

    African Journals Online (AJOL)

    Patterns of seasonal herbaceous biomass change in a burned, ungrazed savanna woodland are reported. A standard clipping technique was used and material farmed in the current season was separated from that formed in the previous season for three perennial grass species: Brachiaria nigropedata, Andropogon ...

  19. Nitrogen cycling in summer active perennial grass systems in South Australia: Non-symbiotic nitrogen fixation

    NARCIS (Netherlands)

    Gupta, V.V.S.R.; Kroker, S.J.; Hicks, M.; Davoren, W.; Descheemaeker, K.K.E.; Llewellyn, R.

    2014-01-01

    Non-symbiotic nitrogen (N2) fixation by diazotrophic bacteria is a potential source for biological N inputs in non-leguminous crops and pastures. Perennial grasses generally add larger quantities of above- and belowground plant residues to soil, and so can support higher levels of soil biological

  20. Novel application of ALMANAC: Modelling a functional group, exotic warm-season perennial grasses

    Science.gov (United States)

    Introduced perennial C4 grasses such buffelgrass (Pennisetum ciliare [(L.) Link]) and old world bluestems (OWB), including genera such as Bothriochloa Kuntze, Capillipedium Stapf, and Dichanthium Willemet have the potential to dominate landscapes. A process-based model that realistically simulates ...

  1. The Perennial Ryegrass GenomeZipper: Targeted Use of Genome Resources for Comparative Grass Genomics1[C][W

    Science.gov (United States)

    Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F.X.; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

    2013-01-01

    Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species. PMID:23184232

  2. A Decade of Carbon Flux Measurements with Annual and Perennial Crop Rotations on the Canadian Prairies

    Science.gov (United States)

    Amiro, B. D.; Tenuta, M.; Gao, X.; Gervais, M.

    2016-12-01

    The Fluxnet database has over 100 cropland sites, some of which have long-term (over a decade) measurements. Carbon neutrality is one goal of sustainable agriculture, although measurements over many annual cropping systems have indicated that soil carbon is often lost. Croplands are complex systems because the CO2 exchange depends on the type of crop, soil, weather, and management decisions such as planting date, nutrient fertilization and pest management strategy. Crop rotations are often used to decrease pest pressure, and can range from a simple 2-crop system, to have 4 or more crops in series. Carbon dioxide exchange has been measured using the flux-gradient technique since 2006 in agricultural systems in Manitoba, Canada. Two cropping systems are being followed: one that is a rotation of annual crops (corn, faba bean, spring wheat, rapeseed, barley, spring wheat, corn, soybean, spring wheat, soybean); and the other with a perennial phase of alfalfa/grass in years 3 to 6. Net ecosystem production ranged from a gain of 330 g C m-2 y-1 in corn to a loss of 75 g C m-2 y-1 in a poor spring-wheat crop. Over a decade, net ecosystem production for the annual cropping system was not significantly different from zero (carbon neutral), but the addition of the perennial phase increased the sink to 130 g C m-2 y-1. Once harvest removals were included, there was a net loss of carbon ranging from 77 g C m-2 y-1 in the annual system to 52 g C m-2 y-1 in the annual-perennial system; but neither of these were significantly different from zero. Termination of the perennial phase of the rotation only caused short-term increases in respiration. We conclude that both these systems were close to carbon-neutral over a decade even though they were tilled with a short growing season (90 to 130 days). We discuss the need for more datasets on agricultural systems to inform management options to increase the soil carbon sink.

  3. Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya

    OpenAIRE

    Opiyo, Francis EO; Ekaya, Wellington N; Nyariki, Dickson M; Mureithi, Stephen Mwangi

    2011-01-01

    Semi-arid rangelands in Kenya are an important source of forage for both domestic and wild animals. However, indigenous perennial grasses notably Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye grass) are disappearing at an alarming rate. Efforts to re-introduce them through restoration programs have often yielded little success. This can partly be attributed to failure of topsoil to capture and store scarce water to me...

  4. The role of changing climate in driving the shift from perennial grasses to annual succulents in a Mediterranean saltmarsh

    NARCIS (Netherlands)

    Strain, E.M.A.; van Belzen, J.; Comandini, P.; Wong, J.; Bouma, T.J.; Airoldi, L.

    2017-01-01

    Changing climate threatens the structure and function of saltmarshes, which are often severely degraded by other human perturbations. Along the Mediterranean coastline, increasing temperature and decreasing rainfall have been hypothesised to trigger habitat shifts from perennial grasses to annual

  5. Uptake of C14-atrazine by prairie grasses in a phytoremediation setting.

    Science.gov (United States)

    Khrunyk, Yuliya; Schiewer, Silke; Carstens, Keri L; Hu, Dingfei; Coats, Joel R

    2017-02-01

    Agrochemicals significantly contribute to environmental pollution. In the USA, atrazine is a widely used pesticide and commonly found in rivers, water systems, and rural wells. Phytoremediation can be a cost-effective means of removing pesticides from soil. The objective of this project was to investigate the ability of prairie grasses to remove atrazine. 14 C-labeled atrazine was added to sterilized sand and water/nutrient cultures, and the analysis was performed after 21 days. Switchgrass and big bluestem were promising species for phytoremediation, taking up about 40% of the applied [ 14 C] in liquid hydroponic cultures, and between 20% and 33% in sand cultures. Yellow Indiangrass showed low resistance to atrazine toxicity and low uptake of [ 14 C] atrazine in liquid hydroponic cultures. Atrazine degradation increased progressively from sand to roots and leaves. Most atrazine taken up by prairie grasses from sand culture was degraded to metabolites, which accounted for 60-80% of [ 14 C] detected in leaves. Deisopropylatrazine (DIA) was the main metabolite detected in sand and roots, whereas in leaves further metabolism took place, forming increased amounts of didealkylatrazine (DDA) and an unidentified metabolite. In conclusion, prairie grasses achieved high atrazine removal and degradation, showing a high potential for phytoremediation.

  6. Comparative assessment of the phytomeliorative efficiency of perennial grasses on chernozems in the transural part of Bashkortostan

    Science.gov (United States)

    Khasanova, R. F.; Suyundukov, Ya. T.; Suyundukova, M. B.

    2010-01-01

    The phytomeliorative efficiency of different groups of perennial herbs was studied. The agrophysical properties of soils under natural grasses (the feather grasses Stipa pennata, S. zalesskii, and S. Lessingiana; the fescue grass Festuca pseudovina; and quack grass), sawn herbs (awnless brome, crested wheat grass, purple alfalfa, the holy clover Onobrychis sibirica, the galega Galega orientalis, and yellow sweet clover), and cereal crops (winter rye and spring wheat) were compared. The formation of the aboveground and underground phytomass and the influence of phytomeliorative herbs on the aggregate state of leached, ordinary, and southern chernozems in the Transural part of Bashkortostan were analyzed.

  7. Comparing soil organic carbon dynamics in perennial grasses and shrubs in a saline-alkaline arid region, northwestern China.

    Science.gov (United States)

    Zhou, Yong; Pei, Zhiqin; Su, Jiaqi; Zhang, Jingli; Zheng, Yuanrun; Ni, Jian; Xiao, Chunwang; Wang, Renzhong

    2012-01-01

    Although semi-arid and arid regions account for about 40% of terrestrial surface of the Earth and contain approximately 10% of the global soil organic carbon stock, our understanding of soil organic carbon dynamics in these regions is limited. A field experiment was conducted to compare soil organic carbon dynamics between a perennial grass community dominated by Cleistogenes squarrosa and an adjacent shrub community co-dominated by Reaumuria soongorica and Haloxylon ammodendron, two typical plant life forms in arid ecosystems of saline-alkaline arid regions in northwestern China during the growing season 2010. We found that both fine root biomass and necromass in two life forms varied greatly during the growing season. Annual fine root production in the perennial grasses was 45.6% significantly higher than in the shrubs, and fine root turnover rates were 2.52 and 2.17 yr(-1) for the perennial grasses and the shrubs, respectively. Floor mass was significantly higher in the perennial grasses than in the shrubs due to the decomposition rate of leaf litter in the perennial grasses was 61.8% lower than in the shrubs even though no significance was detected in litterfall production. Soil microbial biomass and activity demonstrated a strong seasonal variation with larger values in May and September and minimum values in the dry month of July. Observed higher soil organic carbon stocks in the perennial grasses (1.32 Kg C m(-2)) than in the shrubs (1.12 Kg C m(-2)) might be attributed to both greater inputs of poor quality litter that is relatively resistant to decay and the lower ability of microorganism to decompose these organic matter. Our results suggest that the perennial grasses might accumulate more soil organic carbon with time than the shrubs because of larger amounts of inputs from litter and slower return of carbon through decomposition.

  8. A model for backscattering characteristics of tall prairie grass canopies at microwave frequencies

    International Nuclear Information System (INIS)

    Bakhtiari, S.; Zoughi, R.

    1991-01-01

    We have developed a discrete microwave scattering model, describing the radar backscattering coefficient from two treatments (burned and unburned) of tall prairie grass canopies at VV (electric field vector of the transmitted and received signals are vertically oriented) and HH (electric field vector of the transmitted and received signals and horizontally oriented) polarizations, based on the physical, biophysical, and geometrical characteristics of such canopies. Grass blades are modeled as thin and finite dielectric ellipsoids with arbitrary orientations. Scattering by an individual grass blade is formulated using a generalization of the Rayleigh—Gans approximation with a quasistatic solution for the expansion of the interior field. By associating, with each grass blade, various appropriate distribution functions, the relative orientation, location, height, cross section, and permittivity of each grass blade is taken into account. This makes for a more realistic overall description of the canopy. Kirchhoff's surface scattering is used to model the backscatter from the soil surface. An incoherent summation of the effect of grass blades and soil surface is adopted to obtain the total canopy backscattering coefficient, taking into account the attenuation experienced by the signal as it travels through the canopy. The results of this model are given for 1.5, 5, and 10 GHz (L-, C-, and X-band). Although for the shorter wavelengths (X-band) the Rayleigh—Gans criteria is not totally satisfied, nevertheless, the limited available measured X-band data compare relatively well with the results of this model both quantitatively and qualitatively. (author)

  9. Bud-bank and tiller dynamics of co-occurring C3 caespitose grasses in mixed-grass prairie.

    Science.gov (United States)

    Ott, Jacqueline P; Hartnett, David C

    2015-09-01

    Tiller recruitment from the belowground bud bank of caespitose grasses influences their ability to monopolize local resources and, hence, their genet fitness. Differences in bud production and outgrowth among tiller types within a genet and among species may explain co-occurrence of caespitose grasses. This study aimed to characterize genet bud-bank and tiller production and dynamics in two co-occurring species and compare their vegetative reproductive strategies. Bud-bank and tiller dynamics of Hesperostipa comata and Nassella viridula, dominant C3 caespitose grasses in the northern mixed-grass prairie of North America, were assessed throughout an annual cycle. The two species showed similar strategies, maintaining polycyclic tillers and thus creating mixed-age genet bud banks comprising multiple bud cohorts produced in different years. Vegetative tillers produced the majority of buds, whereas flowering tillers contributed little to the bud bank. Buds lived for at least 2 yr and were maintained in multiple developmental stages throughout the year. Because bud longevity rarely exceeded tiller longevity, tiller longevity drove turnover within the bud bank. Tiller population dynamics, more than bud production per tiller, determined the differential contribution of tiller types to the bud bank. Nassella viridula had higher bud production per tiller, a consistent annual tiller recruitment density, and greater longevity of buds on senesced and flowering tillers than H. comata. Co-occurring C3 caespitose grasses had similar bud-bank and tiller dynamics contributing to genet persistence but differed in bud characteristics that could affect genet longevity and species coexistence. © 2015 Botanical Society of America.

  10. Comparing the hydrology of grassed and cultivated catchments in the semi-arid Canadian prairies

    Science.gov (United States)

    van der Kamp, G.; Hayashi, M.; Gallén, D.

    2003-02-01

    At the St Denis National Wildlife Area in the prairie region of southern Saskatchewan, Canada, water levels in wetlands have been monitored since 1968. In 1980 and 1983 a total of about one-third of the 4 km2 area was converted from cultivation to an undisturbed cover of brome grass. A few years after this conversion all the wetlands within the area of grass dried out; they have remained dry since, whereas wetlands in adjacent cultivated lands have held water as before. Field measurements show that introduction of undisturbed grass reduces water input to the wetlands mainly through a combination of efficient snow trapping and enhanced infiltration into frozen soil. In winter, the tall brome grass traps most of the snowfall, whereas in the cultivated fields more wind transport of snow occurs, especially for short stubble and fallow fields. Single-ring infiltration tests were conducted during snowmelt, while the soil was still frozen, and again in summer. The infiltrability of the frozen soil in the grassland is high enough to absorb most or all of the snowmelt, whereas in the cultivated fields the infiltration into the frozen soil is limited and significant runoff occurs. In summer, the infiltrability increases for the cultivated fields, but the grassland retains a much higher infiltrability than the cultivated land. The development of enhanced infiltrability takes several years after the conversion from cultivation to grass, and is likely due to the gradual development of macropores, such as root holes, desiccation cracks, and animal burrows.

  11. Syngas Production from Pyrolysis of Nine Composts Obtained from Nonhybrid and Hybrid Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Adéla Hlavsová

    2014-01-01

    Full Text Available A pyrolysis of compost for the production of syngas with an explicit H2/CO = 2 or H2/CO = 3 was investigated in this study. The composts were obtained from nonhybrid (perennial grasses (NHG and hybrid (perennial grasses (HG. Discrepancies in H2 evolution profiles were found between NHG and HG composts. In addition, positive correlations for NHG composts were obtained between (i H2 yield and lignin content, (ii H2 yield and potassium content, and (iii CO yield and cellulose content. All composts resulted in H2/CO = 2 and five of the nine composts resulted in H2/CO = 3. Exceptionally large higher heating values (HHVs of pyrolysis gas, very close to HHVs of feedstock, were obtained for composts made from mountain brome (MB, 16.23 MJ/kg, hybrid Becva (FB, 16.45 MJ/kg, and tall fescue (TF, 17.43 MJ/kg. The MB and FB composts resulted in the highest syngas formation with H2/CO = 2, whereas TF compost resulted in the highest syngas formation with H2/CO = 3.

  12. Arbuscular common mycorrhizal networks mediate intra- and interspecific interactions of two prairie grasses.

    Science.gov (United States)

    Weremijewicz, Joanna; da Silveira Lobo O'Reilly Sternberg, Leonel; Janos, David P

    2018-01-01

    Arbuscular mycorrhizal fungi form extensive common mycorrhizal networks (CMNs) that may interconnect neighboring root systems of the same or different plant species, thereby potentially influencing the distribution of limiting mineral nutrients among plants. We examined how CMNs affected intra- and interspecific interactions within and between populations of Andropogon gerardii, a highly mycorrhiza dependent, dominant prairie grass and Elymus canadensis, a moderately dependent, subordinate prairie species. We grew A. gerardii and E. canadensis alone and intermixed in microcosms, with individual root systems isolated, but either interconnected by CMNs or with CMNs severed weekly. CMNs, which provided access to a large soil volume, improved survival of both A. gerardii and E. canadensis, but intensified intraspecific competition for A. gerardii. When mixed with E. canadensis, A. gerardii overyielded aboveground biomass in the presence of intact CMNs but not when CMNs were severed, suggesting that A. gerardii with intact CMNs most benefitted from weaker interspecific than intraspecific interactions across CMNs. CMNs improved manganese uptake by both species, with the largest plants receiving the most manganese. Enhanced growth in consequence of improved mineral nutrition led to large E. canadensis in intact CMNs experiencing water-stress, as indicated by 13 C isotope abundance. Our findings suggest that in prairie plant communities, CMNs may influence mineral nutrient distribution, water relations, within-species size hierarchies, and between-species interactions.

  13. Arthropod consumption by small mammals on prairie dog colonies and adjacent ungrazed mixed grass prairie in western South Dakota

    Science.gov (United States)

    W. Agnew; Daniel W. Uresk; R. M. Hansen

    1988-01-01

    The percentage of arthropods and plants in the diets of seven small rodents captured on prairie dog colonies and adjacent mixed grasslands were estimated by microhistological techniques. Arthropod composition over the two year study averaged 51% and 37% on prairie dog colonies and mixed grasslands, respectively. Composition of arthropods on prairie dog colonies was...

  14. Genetic resources of perennial forage grasses in Serbia: Current state, broadening and evaluation

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    Sokolović Dejan

    2017-01-01

    Full Text Available Due to historical background of vegetation development, geographical position, climate and relief, Serbia represents one of the 158 world biodiversity centres, based upon the number of plant species and territory size (biodiversity index 0.72. Large areas in Serbia are under natural grasslands and pastures, composed of forage grass species, and important as source of natural plant genetic diversity and germplasm for breeding. These eco-systems represent basic prerequisites for sustainable forage production, but very low potential of them is utilized and genetic resources are not protected. Family Poaceae is present in Serbia flora with 70 genera and among them from the aspect of forage production and quality, the most important are perennial Festuca, Lolium, Dactylis, Phleum, Bromus, Arrhenatherum, Poa and Agrostis species. Most of these grasses have been bred in Serbia and lot of cultivars were released. These cultivars contain autochthonous Serbian material and represent great and important resource of genetic variability. Therefore, collecting of new samples which are acclimatised to local eco-geographical conditions and including them in plant ex situ gene bank is of exceptional importance for further utilization in different plant breeding programmes as well as genetic resources protection. These autochthonous populations have natural variability and very often have satisfactory yielding performance in comparison with introduced cultivars, which referred them for direct phenotypic selection for cultivars release. Broadening of forage grasses genotypes collection is permanent objective of Serbian scientists. Collected accessions are being characterized and evaluated for important phenological, morphological and agronomical traits. In this paper genetic resources of forage grass species, their diversity and potentials, state of the grasses gene banks, as well as possibility for breeding of new cultivars has been analysed.

  15. Indirect effects of an invasive annual grass on seed fates of two native perennial grass species.

    Science.gov (United States)

    Meyer, Susan E; Merrill, Katherine T; Allen, Phil S; Beckstead, Julie; Norte, Anna S

    2014-04-01

    Invasive plants exhibit both direct and indirect negative effects on recruitment of natives following invasion. We examined indirect effects of the invader Bromus tectorum (cheatgrass) on seed fates of two native grass species, Elymus elymoides and Pseudoroegneria spicata, by removing B. tectorum and by adding inoculum of the shared seed pathogen Pyrenophora semeniperda in factorial experiments at xeric and mesic field sites. We also included a supplemental watering treatment to increase emergence and also the potential for pathogen escape. We recorded emergence and survival of native seedlings and also determined the fate of unemerged seeds. At the xeric site, Pyrenophora-caused mortality was high (34%), and effects of other pathogens and failed emergence of germinants were smaller. Cheatgrass removal negatively affected both emergence (35 vs. 25%) and spring survival (69 vs. 42%). Pyrenophora-caused seed mortality increased with inoculum augmentation for both species (22 vs. 47% overall), but emergence was negatively impacted only for P. spicata (20 vs. 34%). At the mesic site, Pyrenophora-caused mortality was low (6%). Cheatgrass removal doubled emergence (26 vs. 14%). Seed mortality increased significantly with inoculum augmentation for P. spicata (12 vs. 5%) but not E. elymoides, while emergence was not significantly affected in either species. A large fraction of seeds produced germinants that failed to emerge (37%), while another large fraction (35%) was killed by other pathogens. We conclude that facilitation by cheatgrass at the xeric site but interference at the mesic site was probably mediated through litter effects that could be ameliorative or suppressive. Apparent competition between cheatgrass and native grasses could occur through Pyrenophora, especially in a xeric environment, but effects were weak or absent at emergence. This was probably because Pyrenophora attacks the same slow-germinating fraction that is subject to pre-emergence mortality from

  16. Perennial pastures for marginal farming country in southern Queensland. 2. Potential new grass cultivar evaluation

    Directory of Open Access Journals (Sweden)

    Richard G. Silcock

    2015-01-01

    Full Text Available Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production.  Accessions sown at a site were determined by prior experience with them on a range of soils.  High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp.  Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana.  The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species.  While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises.  Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities.Keywords: Herbicide tolerance, persistence, forage yield, establishment ease, commercialization, seed production.DOI: 10.17138/TGFT(315-26

  17. Impacts of managing perennial grasses in the northern Midwest United States for bioenergy on soil organic C and nitrous oxide emission

    Science.gov (United States)

    In the USA perennial grasses [e.g., switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman)] are proposed as cellulosic feedstock. Perennial grasses are often touted as being low input and as having a C-neutral foot print, but managing them as bioenergy feedstock means addin...

  18. Estimating the energy requirements and CO{sub 2} emissions from production of the perennial grasses miscanthus, switchgrass and reed canary grass

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, M.; Metcalfe, P.

    2001-07-01

    The perennial grasses miscanthus, reed canary and swithchgrass have attractions as energy crops in the United Kingdom: all have low demand for fertilizer and pesticide, and are harvested annually. Research on energy ratios and carbon ratios of the grasses is reported. A Microsoft Excel-based model was developed (from an ADAS database) and the input calculations and assumptions are explained. The study demonstrated the attractions of theses grasses as a source of fuel. The results agreed with those from a model developed for the SRC.

  19. Using the Model Perennial Grass Brachypodium sylvaticum to Engineer Resistance to Multiple Abiotic Stresses

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Sean; Reguera, Maria; Sade, Nir; Cartwright, Amy; Tobias, Christian; Thilmony, Roger; Blumwald, Eduardo; Vogel, John

    2015-03-20

    We are using the perennial model grass Brachypodium sylvaticum to identify combinations of transgenes that enhance tolerance to multiple, simultaneous abiotic stresses. The most successful transgene combinations will ultimately be used to create improved switchgrass (Panicum virgatum L.) cultivars. To further develop B. sylvaticum as a perennial model grass, and facilitate our planned transcriptional profiling, we are sequencing and annotating the genome. We have generated ~40x genome coverage using PacBio sequencing of the largest possible size selected libraries (18, 22, 25 kb). Our initial assembly using only long-read sequence contained 320 Mb of sequence with an N50 contig length of 315 kb and an N95 contig length of 40 kb. This assembly consists of 2,430 contigs, the largest of which was 1.6 Mb. The estimated genome size based on c-values is 340 Mb indicating that about 20 Mb of presumably repetitive DNA remains yet unassembled. Significantly, this assembly is far superior to an assembly created from paired-end short-read sequence, ~100x genome coverage. The short-read-only assembly contained only 226 Mb of sequence in 19k contigs. To aid the assembly of the scaffolds into chromosome-scale assemblies we produced an F2 mapping population and have genotyped 480 individuals using a genotype by sequence approach. One of the reasons for using B. sylvaticum as a model system is to determine if the transgenes adversely affect perenniality and winter hardiness. Toward this goal, we examined the freezing tolerance of wild type B. sylvaticum lines to determine the optimal conditions for testing the freezing tolerance of the transgenics. A survey of seven accessions noted significant natural variation in freezing tolerance. Seedling or adult Ain-1 plants, the line used for transformation, survived an 8 hour challenge down to -6 oC and 50% survived a challenge down to -9 oC. Thus, we will be able to easily determine if the transgenes compromise freezing tolerance. In the

  20. Characterization of gene expression associated with drought avoidance and tolerance traits in a perennial grass species.

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    Full Text Available To understand molecular mechanisms of perennial grass adaptation to drought stress, genes associated with drought avoidance or tolerance traits were identified and their expression patterns were characterized in C4 hybrid bermudagrass [Cynodon dactylon (L. Pers.×C. transvaalensis Burtt Davy, cv. Tifway] and common bermudagrass (C. dactylon, cv. C299. Plants of drought-tolerant 'Tifway' and drought-sensitive 'C299' were exposed to drought for 5 d (mild stress and 10 d (severe stress by withholding irrigation in a growth chamber. 'Tifway' maintained significantly lower electrolyte leakage and higher relative water content than 'C299' at both 5 and 10 d of drought stress. Four cDNA libraries via suppression subtractive hybridization analysis were constructed and identified 277 drought-responsive genes in the two genotypes at 5 and 10 d of drought stress, which were mainly classified into the functional categories of stress defense, metabolism, osmoregulation, membrane system, signal and regulator, structural protein, protein synthesis and degradation, and energy metabolism. Quantitative-PCR analysis confirmed the expression of 36 drought up-regulated genes that were more highly expressed in drought-tolerant 'Tifway' than drought-sensitive 'C299', including those for drought avoidance traits, such as cuticle wax formation (CER1 and sterol desaturase, for drought tolerance traits, such as dehydration-protective proteins (dehydrins, HVA-22-like protein and oxidative stress defense (superoxide dismutase, dehydroascorbate reductase, 2-Cys peroxiredoxins, and for stress signaling (EREBP-4 like protein and WRKY transcription factor. The results suggest that the expression of genes for stress signaling, cuticle wax accumulation, antioxidant defense, and dehydration-protective protein accumulation could be critically important for warm-season perennial grass adaptation to long-term drought stress.

  1. The Effect of Heavy Metal Contaminated Soil on Growth and Development of Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Żurek G.

    2013-04-01

    Full Text Available Contamination of agricultural land in Poland by heavy metals is not a general problem but is limited to industrial areas. In regions of long history of industrial emission, of elevated levels of lead, cadmium, zinc and other ions during coal and ore mining and processing, as for example in Silesia, about 10 % of agricultural land may be characterized by exceeded maximum residue limits for Cd, Pb, Cu, Ni and Zn ions. Since the maintenance of agricultural areas in those regions is important from an ecological standpoint, the alternative farming activities are needed. Perennial grass biomass production for energy purposes is currently the best solution for majority of agricultural areas not suitable for food production in Poland. Along with increasing knowledge on separation and utilization of heavy metals (HM during and after biomass processing, phytoremediation of polluted soils will become important and valuable. To detect the effect of soil HM ions concentration on growth and development of selected, tall growing and high biomass yielding perennial grass cultivars, the chlorophyll fluorescence parameters were registered. The elevated content of Pb, Cd and Zn ions in soil influenced on decrease of: minimal (Fo, maximal (Fm and variable (Fv fluorescence level as well as on total complementary area on a diagram of chlorophyll a fluorescence induction curve (Area. Based on detected parameters it was concluded, that the high level of HM ions in soils negatively affected the efficiency of photosynthesis. Therefore, plant growth, as well as development of generative shoots and finally the biomass yield were reduced in some cultivars. Among tested cultivars different reaction for HM ions in polluted soil were noted: from only slightly modified parameters of photosynthesis and unreduced yield (Elytrigia elongata cv. Bamar and Arrhenatherum elatius cv. Wiwena to significantly reduced Fo, Fv, Fm and biomass yield (Bromus carinathus cv. Broma and Bromus

  2. Linking phenology and biomass productivity in South Dakota mixed-grass prairie

    Science.gov (United States)

    Rigge, Matthew; Smart, Alexander; Wylie, Bruce; Gilmanov, Tagir; Johnson, Patricia

    2013-01-01

    Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe plant community condition; the phenology of production can provide inferences on species composition, successional stage, and grazing impacts. We evaluate the productivity and phenology of western South Dakota mixed-grass prairie using 2000 to 2008 Moderate Resolution Imaging Spectrometer (MODIS) normalized difference vegetation index (NDVI) satellite imagery at 250 m spatial resolution. Growing season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool (C3) and warm (C4) season species. Additionally, a variety of phenological indicators including cool season percentage of TIN were derived from the seasonal profiles of NDVI. Cool season percentage and TIN were combined to generate vegetation classes, which served as proxies of plant community condition. TIN decreased with precipitation from east to west across the study area. Alternatively, cool season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of mid-summer precipitation. Cool season TIN averaged 76.8% of total. Seasonal accumulation of TIN corresponded closely (R2 > 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to the TIN and cool season percentage products. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool/warm season composition, and vegetation classes can improve the efficiency of land management by adjusting stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and

  3. Ducks and passerines nesting in northern mixed-grass prairie treated with fire

    Science.gov (United States)

    Grant, Todd A.; Shaffer, Terry L.; Madden, Elizabeth M.; Berkey, Gordon B.

    2011-01-01

    Prescribed fire is an important, ecology-driven tool for restoration of grassland systems. However, prescribed fire remains controversial for some grassland managers because of reported reductions in bird use of recently burned grasslands. Few studies have evaluated effects of fire on grassland bird populations in the northern mixed-grass prairie region. Fewer studies yet have examined the influence of fire on nest density or survival. In our review, we found no studies that simultaneously examined effects of fire on duck and passerine nesting. During 1998—2003, we examined effects of prescribed fire on the density of upland-nesting ducks and passerines nesting in north-central North Dakota, USA. Apparent nest densities of gadwall (Anas strepera), mallard (A. platyrhynchos), and all duck species combined, were influenced by fire history of study units, although the degree of influence was not compelling. Fire history was not related to nest densities of blue-winged teal (A. discors), northern shoveler (A. clypeata), or northern pintail (A. acuta); however, apparent nest densities in relation to the number of postfire growing seasons exhibited a strikingly similar pattern among all duck species. When compared to ducks, fire history strongly influenced apparent nest densities of clay-colored sparrow (Spizella pallida), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus). For most species examined, apparent nest densities were lowest in recently burned units, increased during the second postfire growing season, and stabilized or, in some cases, decreased thereafter. Prescribed fire is critical for restoring the ecology of northern mixed-grass prairies and our findings indicate that reductions in nest densities are limited mostly to the first growing season after fire. Our results support the premise that upland-nesting ducks and several grassland passerine species are adapted to periodic fires occurring at a frequency similar to that

  4. Seasonal variations of cadmium and zinc in Arrhenatherum elatius, a perennial grass species from highly contaminated soils

    International Nuclear Information System (INIS)

    Deram, Annabelle; Denayer, Franck-Olivier; Petit, Daniel; Van Haluwyn, Chantal

    2006-01-01

    There is interest in studying bioaccumulation in plants because they form the base of the food chain as well as their potential use in phytoextraction. From this viewpoint, our study deals with the seasonal variation, from January to July, of Cd and Zn bioaccumulation in three metallicolous populations of Arrhenatherum elatius, a perennial grass with a high biomass production. In heavily polluted soils, while Zn bioaccumulation is weak, A. elatius accumulates more Cd than reported gramineous plants, with concentration of up to 100 μg g -1 . Our results also showed seasonal variations of bioaccumulation, underlying the necessity for in situ studies to specify the date of sampling and also the phenology of the collected plant sample. In our experimental conditions, accumulation is lower in June, leading us to the hypothesis of restriction in heavy metals translocation from roots to aerial parts during seed production. - Cd and Zn bioaccumulation varies seasonally in a perennial grass

  5. Seasonal variations of cadmium and zinc in Arrhenatherum elatius, a perennial grass species from highly contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Deram, Annabelle [Institut Lillois d' Ingenierie de la Sante, Universite Droit et Sante de Lille, EA 2690, 42 rue Ambroise Pare, 59120 Loos (France)]. E-mail: aderam@ilis.univ-lille2.fr; Denayer, Franck-Olivier [Institut Lillois d' Ingenierie de la Sante, Universite Droit et Sante de Lille, EA 2690, 42 rue Ambroise Pare, 59120 Loos (France); Petit, Daniel [Laboratoire de Genetique et Evolution des Populations Vegetales, UPRESA-CNRS 8016, Bat SN2, Universite des Sciences et Techniques de Lille, 59655 Villeneuve d' Ascq, F59655 France (France); Van Haluwyn, Chantal [Faculte des Sciences Pharmaceutiques et Biologiques, Departement de Botanique, Universite Droit et Sante de Lille, EA 2690, B.P. 83, 59006 Lille Cedex (France)

    2006-03-15

    There is interest in studying bioaccumulation in plants because they form the base of the food chain as well as their potential use in phytoextraction. From this viewpoint, our study deals with the seasonal variation, from January to July, of Cd and Zn bioaccumulation in three metallicolous populations of Arrhenatherum elatius, a perennial grass with a high biomass production. In heavily polluted soils, while Zn bioaccumulation is weak, A. elatius accumulates more Cd than reported gramineous plants, with concentration of up to 100 {mu}g g{sup -1}. Our results also showed seasonal variations of bioaccumulation, underlying the necessity for in situ studies to specify the date of sampling and also the phenology of the collected plant sample. In our experimental conditions, accumulation is lower in June, leading us to the hypothesis of restriction in heavy metals translocation from roots to aerial parts during seed production. - Cd and Zn bioaccumulation varies seasonally in a perennial grass.

  6. Water Use and Water-Use Efficiency of Three Perennial Bioenergy Grass Crops in Florida

    Directory of Open Access Journals (Sweden)

    Jerry M. Bennett

    2012-10-01

    Full Text Available Over two-thirds of human water withdrawals are estimated to be used for agricultural production, which is expected to increase as demand for renewable liquid fuels from agricultural crops intensifies. Despite the potential implications of bioenergy crop production on water resources, few data are available on water use of perennial bioenergy grass crops. Therefore, the objective of this study was to compare dry matter yield, water use, and water-use efficiency (WUE of elephantgrass, energycane, and giant reed, grown under field conditions for two growing seasons in North Central Florida. Using scaled sap flow sensor data, water use ranged from about 850 to 1150 mm during the growing season, and was generally greater for giant reed and less for elephantgrass. Despite similar or greater water use by giant reed, dry biomass yields of 35 to 40 Mg ha−1 were significantly greater for energycane and elephantgrass, resulting in greater WUE. Overall, water use by the bioenergy crops was greater than the rainfall received during the study, indicating that irrigation will be needed in the region to achieve optimal yields. Species differ in water use and WUE and species selection can play an important role with regard to potential consequences for water resources.

  7. Growing C4 perennial grass for bioenergy using a new Agro-BGC ecosystem model

    Science.gov (United States)

    di Vittorio, A. V.; Anderson, R. S.; Miller, N. L.; Running, S. W.

    2009-12-01

    Accurate, spatially gridded estimates of bioenergy crop yields require 1) biophysically accurate crop growth models and 2) careful parameterization of unavailable inputs to these models. To meet the first requirement we have added the capacity to simulate C4 perennial grass as a bioenergy crop to the Biome-BGC ecosystem model. This new model, hereafter referred to as Agro-BGC, includes enzyme driven C4 photosynthesis, individual live and dead leaf, stem, and root carbon/nitrogen pools, separate senescence and litter fall processes, fruit growth, optional annual seeding, flood irrigation, a growing degree day phenology with a killing frost option, and a disturbance handler that effectively simulates fertilization, harvest, fire, and incremental irrigation. There are four Agro-BGC vegetation parameters that are unavailable for Panicum virgatum (switchgrass), and to meet the second requirement we have optimized the model across multiple calibration sites to obtain representative values for these parameters. We have verified simulated switchgrass yields against observations at three non-calibration sites in IL. Agro-BGC simulates switchgrass growth and yield at harvest very well at a single site. Our results suggest that a multi-site optimization scheme would be adequate for producing regional-scale estimates of bioenergy crop yields on high spatial resolution grids.

  8. Effects on Environmental and Socioeconomic Sustainability of Producing Ethanol from Perennial Grasses

    Science.gov (United States)

    Dale, V. H.; Parish, E. S.

    2016-12-01

    Using perennial grasses to produce ethanol can enhance progress toward sustainability. A suite of 35 environmental and socioeconomic sustainability indicators was considered in a holistic sustainability assessment of a five-year switchgrass-to-ethanol production experiment centered on a demonstration-scale biorefinery in Vonore, Tennessee. By combining field measurements, literature review and expert opinion, the team was able to rate 28 of the 35 recommended sustainability indicators. The team combined these ratings within a multi-attribute decision support system tool and used this information to compare the sustainability of producing 2118 hectares of no-till switchgrass relative to two alternative business-as-usual scenarios of unmanaged pasture and tilled corn production. The results suggest that East Tennessee switchgrass production improves environmental quality overall and can be beneficial to the counties surrounding the biorefinery in terms of dollars earned and jobs created. The timing of switchgrass production also provides an opportunity to use inactive equipment and laborers. By incorporating a landscape design approach, the opportunities, constraints and most reasonable paths forward for growing bioenergy feedstock in specific context can be assessed in a way that adapts and improves local practices. Lessons learned from this case study are being incorporated into sustainability assessments of corn stover in Iowa and a variety of bioenergy feedstocks in diverse settings. The overall goal is to develop sound management practices that can address the multiple and sometimes competing demands of stakeholders.

  9. Internal iron biomineralization in Imperata cylindrica, a perennial grass: chemical composition, speciation and plant localization.

    Science.gov (United States)

    Rodríguez, N; Menéndez, N; Tornero, J; Amils, R; de la Fuente, V

    2005-03-01

    * The analysis of metal distribution in Imperata cylindrica, a perennial grass isolated from the banks of Tinto River (Iberian Pyritic Belt), an extreme acidic environment with high content in metals, has shown a remarkable accumulation of iron. This property has been used to study iron speciation and its distribution among different tissues and structures of the plant. * Mossbauer (MS) and X-ray diffraction (XRD) were used to determine the iron species, scanning electron microscopy (SEM) to locate iron biominerals among plant tissue structures, and energy-dispersive X-ray microanalysis (EDAX), X-ray fluorescence (TXRF) and inductively coupled plasma emission spectroscopy (ICP-MS) to confirm their elemental composition. * The MS spectral analysis indicated that iron accumulated in this plant mainly as jarosite and ferritin. The presence of jarosite was confirmed by XRD and the distribution of both minerals in structures of different tissues was ascertained by SEM-EDAX analysis. * The convergent results obtained by complementary techniques suggest a complex iron management system in I. cylindrica, probably as a consequence of the environmental conditions of its habitat.

  10. Effects of herbivory on the reproductive effort of 4 prairie perennials

    Directory of Open Access Journals (Sweden)

    Bradley Kate L

    2002-02-01

    Full Text Available Abstract Background Herbivory can affect every aspect of a plant's life. Damaged individuals may show decreased survivorship and reproductive output. Additionally, specific plant species (legumes and tissues (flowers are often selectively targeted by herbivores, like deer. These types of herbivory influence a plant's growth and abundance. The objective of this study was to identify the effects of leaf and meristem removal (simulated herbivory within an exclosure on fruit and flower production in four species (Rhus glabra, Rosa arkansana, Lathyrus venosus, and Phlox pilosa which are known targets of deer herbivory. Results Lathyrus never flowered or went to seed, so we were unable to detect any treatment effects. Leaf removal did not affect flower number in the other three species. However, Phlox, Rosa, and Rhus all showed significant negative correlations between seed mass and leaf removal. Meristem removal had a more negative effect than leaf removal on flower number in Phlox and on both flower number and seed mass in Rosa. Conclusions Meristem removal caused a greater response than defoliation alone in both Phlox and Rosa, which suggests that meristem loss has a greater effect on reproduction. The combination of leaf and meristem removal as well as recruitment limitation by deer, which selectively browse for these species, is likely to be one factor contributing to their low abundance in prairies.

  11. Investigation of the Transcriptome of Prairie Cord Grass, a New Cellulosic Biomass Crop

    KAUST Repository

    Gedye, Kristene; Gonzalez-Hernandez, Jose; Ban, Yuguang; Ge, Xijin; Thimmapuram, Jyothi; Sun, Fengjie; Wright, Chris; Ali, Shahjahan; Boe, Arvid; Owens, Vance

    2010-01-01

    in this paper describes the first investigation of the transcriptome of prairie cordgrass via Next Generation Sequencing Technology, 454 GS FLX. A total of 556,198 expressed sequence tags (ESTs) were produced from four prairie cordgrass tissues: roots, rhizomes

  12. SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

    Energy Technology Data Exchange (ETDEWEB)

    L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK

    2004-01-01

    Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

  13. Transcriptome Analysis in Sheepgrass (Leymus chinensis). A Dominant Perennial Grass of the Eurasian Steppe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuangyan [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing; Huang, Xin [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing; Yang, Xiaohan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Gongshe [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing

    2013-07-04

    BACKGROUND: Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. RESULTS: The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. CONCLUSIONS: This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  14. Transcriptome analysis in sheepgrass (Leymus chinensis): a dominant perennial grass of the Eurasian Steppe.

    Science.gov (United States)

    Chen, Shuangyan; Huang, Xin; Yan, Xueqing; Liang, Ye; Wang, Yuezhu; Li, Xiaofeng; Peng, Xianjun; Ma, Xingyong; Zhang, Lexin; Cai, Yueyue; Ma, Tian; Cheng, Liqin; Qi, Dongmei; Zheng, Huajun; Yang, Xiaohan; Li, Xiaoxia; Liu, Gongshe

    2013-01-01

    Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  15. Crop-associated virus reduces the rooting depth of non-crop perennial native grass more than non-crop-associated virus with known viral suppressor of RNA silencing (VSR).

    Science.gov (United States)

    Malmstrom, Carolyn M; Bigelow, Patrick; Trębicki, Piotr; Busch, Anna K; Friel, Colleen; Cole, Ellen; Abdel-Azim, Heba; Phillippo, Colin; Alexander, Helen M

    2017-09-15

    As agricultural acreage expanded and came to dominate landscapes across the world, viruses gained opportunities to move between crop and wild native plants. In the Midwestern USA, virus exchange currently occurs between widespread annual Poaceae crops and remnant native perennial prairie grasses now under consideration as bioenergy feedstocks. In this region, the common aphid species Rhopalosiphum padi L. (the bird cherry-oat aphid) transmits several virus species in the family Luteoviridae, including Barley yellow dwarf virus (BYDV-PAV, genus Luteovirus) and Cereal yellow dwarf virus (CYDV-RPV and -RPS, genus Polerovirus). The yellow dwarf virus (YDV) species in these two genera share genetic similarities in their 3'-ends, but diverge in the 5'-regions. Most notably, CYDVs encode a P0 viral suppressor of RNA silencing (VSR) absent in BYDV-PAV. Because BYDV-PAV has been reported more frequently in annual cereals and CYDVs in perennial non-crop grasses, we examine the hypothesis that the viruses' genetic differences reflect different affinities for crop and non-crop hosts. Specifically, we ask (i) whether CYDVs might persist within and affect a native non-crop grass more strongly than BYDV-PAV, on the grounds that the polerovirus VSR could better moderate the defenses of a well-defended perennial, and (ii) whether the opposite pattern of effects might occur in a less defended annual crop. Because previous work found that the VSR of CYDV-RPS possessed greater silencing suppressor efficiency than that of CYDV-RPV, we further explored (iii) whether a novel grass-associated CYDV-RPS isolate would influence a native non-crop grass more strongly than a comparable CYDV-RPV isolate. In growth chamber studies, we found support for this hypothesis: only grass-associated CYDV-RPS stunted the shoots and crowns of Panicum virgatum L. (switchgrass), a perennial native North American prairie grass, whereas crop-associated BYDV-PAV (and coinfection with BYDV-PAV and CYDV-RPS) most

  16. Alien plant invasion in mixed-grass prairie: Effects of vegetation type and anthropogenic disturbance

    Science.gov (United States)

    Larson, D.L.; Anderson, P.J.; Newton, W.

    2001-01-01

    The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of

  17. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman

    2016-01-01

    with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N......A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized...... carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground...

  18. Sparrow nest survival in relation to prescribed fire and woody plant invasion in a northern mixed-grass prairie

    Science.gov (United States)

    Murphy, Robert K.; Shaffer, Terry L.; Grant, Todd A.; Derrig, James L.; Rubin, Cory S.; Kerns, Courtney K.

    2017-01-01

    Prescribed fire is used to reverse invasion by woody vegetation on grasslands, but managers often are uncertain whether influences of shrub and tree reduction outweigh potential effects of fire on nest survival of grassland birds. During the 2001–2003 breeding seasons, we examined relationships of prescribed fire and woody vegetation to nest survival of clay-colored sparrow (Spizella pallida) and Savannah sparrow (Passerculus sandwichensis) in mixed-grass prairie at Des Lacs National Wildlife Refuge in northwestern North Dakota, USA. We assessed relationships of nest survival to 1) recent fire history, in terms of number of breeding seasons (2, 3, or 4–5) since the last prescribed fire, and 2) prevalence of trees and tall (>1.5 m) shrubs in the landscape and of low (≤1.5 m) shrubs within 5 m of nests. Nest survival of both species exhibited distinct patterns related to age of the nest and day of year, but bore no relationship to fire history. Survival of clay-colored sparrow nests declined as the amount of trees and tall shrubs within 100 m increased, but we found no relationship to suggest nest parasitism by brown-headed cowbirds (Molothrus ater) as an underlying mechanism. We found little evidence linking nest survival of Savannah sparrow to woody vegetation. Our results suggest that fire can be used to restore northern mixed-grass prairies without adversely affecting nest survival of ≥2 widespread passerine species. Survival of nests of clay-colored sparrow may increase when tall woody cover is reduced by fire. Our data lend support to the use of fire for reducing scattered patches of tall woody cover to enhance survival of nests of ≥1 grassland bird species in northern mixed-grass prairies, but further study is needed that incorporates experimental approaches and assessments of shorter term effects of fire on survival of nests of grassland passerines.

  19. Ecosystem engineering varies spatially: a test of the vegetation modification paradigm for prairie dogs

    Science.gov (United States)

    Baker, Bruce W.; Augustine, David J.; Sedgwick, James A.; Lubow, Bruce C.

    2013-01-01

    Colonial, burrowing herbivores can be engineers of grassland and shrubland ecosystems worldwide. Spatial variation in landscapes suggests caution when extrapolating single-place studies of single species, but lack of data and the need to generalize often leads to ‘model system’ thinking and application of results beyond appropriate statistical inference. Generalizations about the engineering effects of prairie dogs (Cynomys sp.) developed largely from intensive study at a single complex of black-tailed prairie dogs C. ludovicianus in northern mixed prairie, but have been extrapolated to other ecoregions and prairie dog species in North America, and other colonial, burrowing herbivores. We tested the paradigm that prairie dogs decrease vegetation volume and the cover of grasses and tall shrubs, and increase bare ground and forb cover. We sampled vegetation on and off 279 colonies at 13 complexes of 3 prairie dog species widely distributed across 5 ecoregions in North America. The paradigm was generally supported at 7 black-tailed prairie dog complexes in northern mixed prairie, where vegetation volume, grass cover, and tall shrub cover were lower, and bare ground and forb cover were higher, on colonies than at paired off-colony sites. Outside the northern mixed prairie, all 3 prairie dog species consistently reduced vegetation volume, but their effects on cover of plant functional groups varied with prairie dog species and the grazing tolerance of dominant perennial grasses. White-tailed prairie dogs C. leucurus in sagebrush steppe did not reduce shrub cover, whereas black-tailed prairie dogs suppressed shrub cover at all complexes with tall shrubs in the surrounding habitat matrix. Black-tailed prairie dogs in shortgrass steppe and Gunnison's prairie dogs C. gunnisoni in Colorado Plateau grassland both had relatively minor effects on grass cover, which may reflect the dominance of grazing-tolerant shortgrasses at both complexes. Variation in modification of

  20. Evaluation of the greenhouse effect gases (CO2, CH4, N2O) in grass land and in the grass breeding. Greenhouse effect gases prairies. report of the first part of the project December 2002

    International Nuclear Information System (INIS)

    Soussana, J.F.

    2002-12-01

    In the framework of the Kyoto protocol on the greenhouse effect gases reduction, many ecosystems as the prairies can play a main role for the carbon sequestration in soils. The conservation of french prairies and their management adaptation could allow the possibility of carbon sequestration in the soils but also could generate emissions of CO 2 and CH 4 (by the breeding animals on grass) and N 2 O (by the soils). This project aims to establish a detailed evaluation of the contribution of the french prairies to the the greenhouse effect gases flux and evaluate the possibilities of reduction of the emissions by adaptation of breeding systems. (A.L.B.)

  1. Summer water use by California coastal prairie grasses: fog, drought, and community composition.

    Science.gov (United States)

    Corbin, Jeffrey D; Thomsen, Meredith A; Dawson, Todd E; D'Antonio, Carla M

    2005-10-01

    Plants in the Mediterranean climate region of California typically experience summer drought conditions, but correlations between zones of frequent coastal fog inundation and certain species' distributions suggest that water inputs from fog may influence species composition in coastal habitats. We sampled the stable H and O isotope ratios of water in non-photosynthetic plant tissue from a variety of perennial grass species and soil in four sites in northern California in order to determine the proportion of water deriving from winter rains and fog during the summer. The relationship between H and O stable isotopes from our sample sites fell to the right of the local meteoric water line (LMWL) during the summer drought, providing evidence that evaporation of water from the soil had taken place prior to the uptake of water by vegetation. We developed a novel method to infer the isotope values of water before it was subjected to evaporation in which we used experimental data to calculate the slope of the deltaH versus deltaO line versus the LMWL. After accounting for evaporation, we then used a two-source mixing model to evaluate plant usage of fog water. The model indicated that 28-66% of the water taken up by plants via roots during the summer drought came from fog rather than residual soil water from winter rain. Fog use decreased as distance from the coast increased, and there were significant differences among species in the use of fog. Rather than consistent differences in fog use by species whose distributions are limited to the coast versus those with broader distributions, species responded individualistically to summer fog. We conclude that fogwater inputs can mitigate the summer drought in coastal California for many species, likely giving an advantage to species that can use it over species that cannot.

  2. Downy brome control and impacts on perennial grass abundance: a systematic review spanning 64 years

    Science.gov (United States)

    Given the high cost of restoration and the underlying assumption that reducing annual grass abundance is a necessary precursor to rangeland restoration in the Intermountain West, USA, we sought to identify limitations and strengths of annual grass and woody plant reduction methods and refine future ...

  3. Lignin and etherified ferulates impact digestibility and structural composition of three temperate perennial grasses

    Science.gov (United States)

    Breeding grasses for increased digestibility increases their value and profitability in ruminant livestock production systems. Digestibility can be improved in grasses by either increasing the concentration of soluble and readily fermentable carbohydrates or by altering the plant cell wall to create...

  4. Investigation of the Transcriptome of Prairie Cord Grass, a New Cellulosic Biomass Crop

    Directory of Open Access Journals (Sweden)

    Kristene Gedye

    2010-09-01

    Full Text Available Prairie cordgrass ( Bosc ex Link is being developed as a cellulosic biomass crop. Development of this species will require numerous steps, including breeding, agronomy, and characterization of the species genome. The research in this paper describes the first investigation of the transcriptome of prairie cordgrass via Next Generation Sequencing Technology, 454 GS FLX. A total of 556,198 expressed sequence tags (ESTs were produced from four prairie cordgrass tissues: roots, rhizomes, immature inflorescence, and hooks. These ESTs were assembled into 26,302 contigs and 71,103 singletons. From these data were identified, EST–SSR (simple sequence repeat regions and cell wall biosynthetic pathway genes suitable for the development of molecular markers which can aid the breeding process of prairie cordgrass by means of marker assisted selection.

  5. Investigation of the Transcriptome of Prairie Cord Grass, a New Cellulosic Biomass Crop

    KAUST Repository

    Gedye, Kristene

    2010-09-15

    Prairie cordgrass (Spartina pectinata Bosc ex Link) is being developed as a cellulosic biomass crop. Development of this species will require numerous steps, including breeding, agronomy, and characterization of the species genome. The research in this paper describes the first investigation of the transcriptome of prairie cordgrass via Next Generation Sequencing Technology, 454 GS FLX. A total of 556,198 expressed sequence tags (ESTs) were produced from four prairie cordgrass tissues: roots, rhizomes, immature inflorescence, and hooks. These ESTs were assembled into 26,302 contigs and 71,103 singletons. From these data were identified, EST-SSR (simple sequence repeat) regions and cell wall biosynthetic pathway genes suitable for the development of molecular markers which can aid the breeding process of prairie cordgrass by means of marker assisted selection.

  6. Gene Flow in Genetically Engineered Perennial Grasses: Lessons for Modification of Dedicated Bioenergy Crops

    Science.gov (United States)

    Genetic modification of dedicated bioenergy crops, such as switchgrass, will play a major role in crop improvement for a wide range of beneficial traits specific to biofuels. One obstacle that arises regarding transgenic improvement of perennials used for biofuels is the propensity of these plants t...

  7. Soil amendment effects on the exotic annual grass Bromus tectorum L. and facilitation of its growth by the native perennial grass Hilaria jamesii (Torr.) Benth

    Science.gov (United States)

    Belnap, J.; Sherrod, S.K.

    2009-01-01

    Greenhouse experiments were undertaken to identify soil factors that curtail growth of the exotic annual grass Bromus tectorum L. (cheatgrass) without significantly inhibiting growth of native perennial grasses (here represented by Hilaria jamesii [Torr.] Benth). We grew B. tectorum and H. jamesii alone (monoculture pots) and together (combination pots) in soil treatments that manipulated levels of soil phosphorus, potassium, and sodium. Hilaria jamesii showed no decline when its aboveground biomass in any of the applied treatments was compared to the control in either the monoculture or combination pots. Monoculture pots of B. tectorum showed a decline in aboveground biomass with the addition of Na2HPO4 and K2HPO4. Interestingly, in pots where H. jamesii was present, the negative effect of these treatments was ameliorated. Whereas the presence of B. tectorum generally decreased the aboveground biomass of H. jamesii (comparing aboveground biomass in monoculture versus combination pots), the presence of H. jamesii resulted in an enhancement of B. tectorum aboveground biomass by up to 900%. We hypothesize that B. tectorum was able to obtain resources from H. jamesii, an action that benefited B. tectorum while generally harming H. jamesii. Possible ways resources may be gained by B. tectorum from native perennial grasses include (1) B. tectorum is protected from salt stress by native plants or associated soil biota; (2) when B. tectorum is grown with H. jamesii, the native soil biota is altered in a way that favors B. tectorum growth, including B. tectorum tapping into the mycorrhizal network of native plants and obtaining resources from them; (3) B. tectorum can take advantage of root exudates from native plants, including water and nutrients released by natives via hydraulic redistribution; and (4) B. tectorum is able to utilize some combination of the above mechanisms. In summary, land managers may find adding soil treatments can temporarily suppress B. tectorum

  8. Effects of prescribed burning and litter type on litter decomposition and nutrient release in mixed-grass prairie in Eastern Montana

    Science.gov (United States)

    Fire can affect litter decomposition and carbon (C) and nitrogen (N) dynamics. Here, we examined the effect of summer fire and three litter types on litter decomposition and litter C and N dynamics in a northern mixed-grass prairie over a 24 month period starting ca. 14 months after fire. Over all...

  9. Genes and quantitative trait loci (QTL) controlling trace element concentrations in perennial grasses grown on phytotoxic soil contaminated with heavy metals

    Science.gov (United States)

    Perennial grasses cover diverse soils throughout the world, including sites contaminated with heavy metals, producing forages that must be safe for livestock and wildlife. Chromosome regions known as quantitative trait loci (QTLs) controlling forage mineral concentrations were mapped in a populatio...

  10. Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: I. Perennial shrubs and grasses

    Science.gov (United States)

    Berry, Kristin H.; Weigand, James F.; Gowan, Timothy A.; Mack, Jeremy S.

    2015-01-01

    We studied recovery of 21 perennial plant species along a severely disturbed aqueduct corridor in a Larrea tridentata-Ambrosia dumosa plant alliance in the Mojave Desert 36 years after construction. The 97-m wide corridor contained a central dirt road and buried aqueduct pipeline. We established transects at 0 m (road verge), 20 m and 40 m into the disturbance corridor, and at 100 m in undisturbed habitat (the control). Although total numbers of shrubs per transect did not vary significantly with distance from the verge, canopy cover of shrubs, species richness, and species diversity were higher in the control than at the verge and other distances. Canopy cover of common shrubs (Ericameria nauseosa, Ambrosia salsola, A. dumosa, L. tridentata, Grayia spinosa) and perennial grasses (Elymus elymoides, Poa secunda) also varied significantly by location. Discriminant analysis clearly separated the four distances based on plant composition. Patterns of recovery were bidirectional: secondary succession from the control into the disturbance corridor and inhibition from the verge in the direction of the control. Time estimated for species composition to resemble the control is dependent on location within the disturbance corridor and could be centuries at the road verge. Our findings have applications to other deserts.

  11. Abiotic factors affect the recruitment and biomass of perennial grass and evergreen shrub seedlings in denuded areas of Patagonian Monte rangelands.

    Science.gov (United States)

    Bosco, Tomás; Bertiller, Mónica Beatriz; Carrera, Analía Lorena

    2018-07-15

    Assessing the ability of key species to cope with environmental stresses in disturbed areas is an important issue for recovery of degraded arid ecosystem. Our objective was to evaluate the effect of soil moisture, exposure to UV radiation, and presence/absence of litter with different chemistry on soil N, recruitment and biomass of seedlings of perennial grass (Poa ligularis and Nassella tenuis) and evergreen shrub species (Atriplex lampa and Larrea divaricata) in denuded areas. We carried out a microcosm experiment with soil blocks (28 cm depth) sowed with seeds of the target species, subjected to different levels of litter type (perennial grass-evergreen shrub mixture, evergreen shrub mixture, and no litter), UV radiation (near ambient and reduced UV), and soil water (high: 15-25% and low 5-15%). Periodically, during 6 months, we assessed soil-N (total and inorganic) at two depths and species seedling recruitment at microcosms. Additionally, emerged seedlings of each species were transplanted to individual pots containing soil and subjected to the same previous factors during 12 months. Then, all plants were harvested and biomass assessed. Only inorganic soil-N at the upper soil varied among treatments increasing with the presence of evergreen shrub litter, exposure to ambient UV, and high soil water. Inorganic soil-N, promoted by near ambient UV and high soil water, had a positive effect on recruitment of perennial grasses and A. lampa. Both litter types promoted the recruitment of perennial grasses. Evergreen shrub litter and high soil water promoted the recruitment of L. divaricata. Seedling biomass of perennial grasses increased with high soil water and reduced UV. Ambient UV had positive or null effects on biomass of evergreen shrub seedlings. High soil water increased biomass of L. divaricata seedlings. We concluded that soil water appeared as the most limiting factor for seedling recruitment of all species whereas inorganic soil N limited the

  12. Perennial grasses as the ecological link for preserving the fertility of the peat soils polluted by radionuclides

    International Nuclear Information System (INIS)

    Podolyak, A.G.; Saraseko, E.G.; Arastovich, T.V.; Suzko, O.V.; Tagaj, S.A.; Lasko, T.V.; Goloveshkin, V.V.

    2011-01-01

    The problem of degradation of peat soils polluted with 137Cs and 90Sr and cultivation of the crop production on them is considered. Distribution of grasslands and pastures on polluted peat soils by the regions of the Republic of Belarus is presented. Characteristics of the peat soils are shown. Coefficients of migration of radionuclides in perennial grasses' hay depending on mobile potassium availability (for 137Cs) and soil reaction pHkci (for 90sr) are evaluated. Inadequacy of the hay, harvested on polluted territories, to the main quality characteristics is presented and analyzed. Crop mixtures recommended for grasslands and pastures reseeding on polluted territories are suggested. The list of cultivars suitable for the conditions of over wetting is offered. It is recommended to use shallow peat soils as grasslands. Permanent cereal grasses restore organic matter of these soils and provide economic efficiency of agricultural use. According the results of the research the transfer factors of 137Cs and 90Sr to plants are relatively low. This fact is explained by the time that has passed since the accident on Chernobyl nuclear power plant and by the variations of mobile potassium and exchangeable acidity in peat soils

  13. Life cycle analysis of multi-crop lignocellulosic material (perennial grasses) for bioethanol production in western Canada : a review.

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, A. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering; Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK (Canada). Bioproducts and Bioprocessing; Panigrahi, S. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering; Mupondwa, E.K. [Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK (Canada). Bioproducts and Bioprocessing

    2009-07-01

    This paper presented a life cycle assessment of multi-crop lignocellulosic biomass to determine the environmental performance of a bioethanol biorefinery in western Canada. The study investigated the economic aspects of the ethanol fuel system such as biorefinery operating costs and possible improvements in biorefinery economics resulting from pretreatment, hydrolysis, and fermentation processes. The eco-efficiency was determined by comparing economic parameters with selected environmental parameters. The study also compared the efficiency of the lignoce lulosic biorefinery with grain-based dry milling ethanol plants that produce ethanol as well as dried grains and solubles used as animal feed. The study showed that the choice of feedstock and location of the biorefinery is very important. The location should be carefully chosen where there is no water shortage. Various low valued lignocellulosic energy crops such as switch grass, alfalfa, and other perennial grasses can grow in marginal or pasture land and can decrease production costs considerably, thus improving the economic viability of biorefineries. The use of co-products can also add value to the process and can decrease the cost of ethanol production. tabs., figs.

  14. Perennial grass management impacts on runoff and sediment export from vegetated channels in pulse flow runoff events

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, H.M. [Department of Agriculture and Natural Resources, University of Minnesota-Crookston, 2900 University Avenue, Crookston, MN 56716 (United States); Cruse, R.M.; Burras, C.L. [Agronomy Department, Iowa State University, Ames, IA 50010-1010 (United States)

    2011-01-15

    The goal of the United States Congress is to replace 30% of United States petroleum with biofuels by 2030. If this goal will be accomplished, it is estimated that 25-50% of the land enrolled in the Conservation Reserve Program (CRP) have its biomass removed. However, the purpose of many conservation practices enrolled in CRP is to improve or maintain water quality and not to serve as a source of biomass. This study was conducted to determine if biomass removal has an effect on runoff and sediment export from vegetated channels during low intensity storms that occur frequently. In June 2006, 24 channels were created that measured 2 m x 10 m. The treatments of grass species (big bluestem, corn, smooth bromegrass, and switchgrass) and biomass removal (removed, not removed) were applied to the channels in a split-plot arrangement. Three times in 2007 and 3 more times in 2008, a 787 L load of water with suspended sediment was drained on the head and sides of each experimental unit and the entire load of water that ran off was collected, weighed, and sampled for sediment concentration. Biomass removal increased runoff and sediment by an average of 15% over the two years of the study. The channels planted to perennial C4 grasses were most effective at reducing runoff and sediment export, while the corn was consistently the least effective at reducing runoff and sediment export. (author)

  15. Perennial grass management impacts on runoff and sediment export from vegetated channels in pulse flow runoff events

    International Nuclear Information System (INIS)

    Wilson, H.M.; Cruse, R.M.; Burras, C.L.

    2011-01-01

    The goal of the United States Congress is to replace 30% of United States petroleum with biofuels by 2030. If this goal will be accomplished, it is estimated that 25-50% of the land enrolled in the Conservation Reserve Program (CRP) have its biomass removed. However, the purpose of many conservation practices enrolled in CRP is to improve or maintain water quality and not to serve as a source of biomass. This study was conducted to determine if biomass removal has an effect on runoff and sediment export from vegetated channels during low intensity storms that occur frequently. In June 2006, 24 channels were created that measured 2 m x 10 m. The treatments of grass species (big bluestem, corn, smooth bromegrass, and switchgrass) and biomass removal (removed, not removed) were applied to the channels in a split-plot arrangement. Three times in 2007 and 3 more times in 2008, a 787 L load of water with suspended sediment was drained on the head and sides of each experimental unit and the entire load of water that ran off was collected, weighed, and sampled for sediment concentration. Biomass removal increased runoff and sediment by an average of 15% over the two years of the study. The channels planted to perennial C4 grasses were most effective at reducing runoff and sediment export, while the corn was consistently the least effective at reducing runoff and sediment export. (author)

  16. Understanding the Impacts of AFEX™ Pretreatment and Densification on the Fast Pyrolysis of Corn Stover, Prairie Cord Grass, and Switchgrass.

    Science.gov (United States)

    Sundaram, Vijay; Muthukumarappan, Kasiviswanathan; Gent, Stephen

    2017-03-01

    Lignocellulosic feedstocks corn stover, prairie cord grass, and switchgrass were subjected to ammonia fiber expansion (AFEX™) pretreatment and densified using extrusion pelleting and ComPAKco densification technique. The effects of AFEX™ pretreatment and densification were studied on the fast pyrolysis product yields. Feedstocks were milled in a hammer mill using three different screen sizes (2, 4, and 8 mm) and were subjected to AFEX™ pretreatment. The untreated and AFEX™-pretreated feedstocks were moisture adjusted at three levels (5, 10, and 15 % wb) and were extruded using a lab-scale single screw extruder. The barrel temperature of the extruder was maintained at 75, 100, and 125 °C. Durability of the extruded pellets made from AFEX™-pretreated corn stover, prairie cord grass, and switchgrass varied from 94.5 to 99.2, 94.3 to 98.7, and 90.1 to 97.5 %, respectively. Results of the thermogravimetric analysis showed the decrease in the decomposition temperature of the all the feedstocks after AFEX™ pretreatment indicating the increase in thermal stability. Loose and densified feedstocks were subjected to fast pyrolysis in a lab-scale reactor, and the yields (bio-oil and bio-char) were measured. Bio-char obtained from the AFEX™-pretreated feedstocks exhibited increased bulk and particle density compared to the untreated feedstocks. The properties of the bio-oil were statistically similar for the untreated, AFEX™-pretreated, and AFEX™-pretreated densified feedstocks. Based on the bio-char and bio-oil yields, the AFEX™-pretreated feedstocks and the densified AFEX™-pretreated feedstocks (pellets and PAKs) exhibited similar behavior. Hence, it can be concluded that densifying the AFEX™-pretreated feedstocks could be a viable option in the biomass-processing depots to reduce the transportation costs and the logistical impediments without affecting the product yields.

  17. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings. Copyright © 2015. Published by Elsevier B.V.

  18. Differential metabolic responses of perennial grass Cynodon transvaalensis×Cynodon dactylon (C₄) and Poa Pratensis (C₃) to heat stress.

    Science.gov (United States)

    Du, Hongmei; Wang, Zhaolong; Yu, Wenjuan; Liu, Yimin; Huang, Bingru

    2011-03-01

    Differential metabolic responses to heat stress may be associated with variations in heat tolerance between cool-season (C₃) and warm-season (C₄) perennial grass species. The main objective of this study was to identify metabolites associated with differential heat tolerance between C₄ bermudagrass and C₃ Kentucky bluegrass by performing metabolite profile analysis using gas chromatography-mass spectrometry. Plants of Kentucky bluegrass (Poa Pratensis'Midnight') and hybrid bermudagrass (Cynodon transvaalensis x Cynodon dactylon'Tifdwarf') were grown under optimum temperature conditions (20/15 °C for Kentucky bluegrass and 30/25 °C for bermudagrass) or heat stress (35/30 °C for Kentucky bluegrass and 45/40 °C for bermudagrass). Physiological responses to heat stress were evaluated by visual rating of grass quality, measuring photochemical efficiency (variable fluorescence to maximal fluorescence) and electrolyte leakage. All of these parameters indicated that bermudagrass exhibited better heat tolerance than Kentucky bluegrass. The metabolite analysis of leaf polar extracts revealed 36 heat-responsive metabolites identified in both grass species, mainly consisting of organic acids, amino acids, sugars and sugar alcohols. Most metabolites showed higher accumulation in bermudagrass compared with Kentucky bluegrass, especially following long-term (18 days) heat stress. The differentially accumulated metabolites included seven sugars (sucrose, fructose, galactose, floridoside, melibiose, maltose and xylose), a sugar alcohol (inositol), six organic acids (malic acid, citric acid, threonic acid, galacturonic acid, isocitric acid and methyl malonic acid) and nine amino acids (Asn, Ala, Val, Thr, γ-aminobutyric acid, IIe, Gly, Lys and Met). The differential accumulation of those metabolites could be associated with the differential heat tolerance between C₃ Kentucky bluegrass and C₄ bermudagrass. Copyright © Physiologia Plantarum 2010.

  19. Germination sensitivities to water potential among co-existing C3 and C4 grasses of cool semi-arid prairie grasslands.

    Science.gov (United States)

    Mollard, F P O; Naeth, M A

    2015-03-01

    An untested theory states that C4 grass seeds could germinate under lower water potentials (Ψ) than C3 grass seeds. We used hydrotime modelling to study seed water relations of C4 and C3 Canadian prairie grasses to address Ψ divergent sensitivities and germination strategies along a risk-spreading continuum of responses to limited water. C4 grasses were Bouteloua gracilis, Calamovilfa longifolia and Schizachyrium scoparium; C3 grasses were Bromus carinatus, Elymus trachycaulus, Festuca hallii and Koeleria macrantha. Hydrotime parameters were obtained after incubation of non-dormant seeds under different Ψ PEG 6000 solutions. A t-test between C3 and C4 grasses did not find statistical differences in population mean base Ψ (Ψb (50)). We found idiosyncratic responses of C4 grasses along the risk-spreading continuum. B. gracilis showed a risk-taker strategy of a species able to quickly germinate in a dry soil due to its low Ψb (50) and hydrotime (θH ). The high Ψb (50) of S. scoparium indicates it follows the risk-averse strategy so it can only germinate in wet soils. C. longifolia showed an intermediate strategy: the lowest Ψb (50) yet the highest θH . K. macrantha, a C3 grass which thrives in dry habitats, had the highest Ψb (50), suggesting a risk-averse strategy for a C3 species. Other C3 species showed intermediate germination patterns in response to Ψ relative to C4 species. Our results indicate that grasses display germination sensitivities to Ψ across the risk-spreading continuum of responses. Thus seed water relations may be poor predictors to explain differential recruitment and distribution of C3 and C4 grasses in the Canadian prairies. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Perennial Grass and Native Wildflowers: A Synergistic Approach to Habitat Management

    Directory of Open Access Journals (Sweden)

    Shereen S. Xavier

    2017-09-01

    Full Text Available Marginal agricultural land provides opportunities to diversify landscapes by producing biomass for biofuel, and through floral provisioning that enhances arthropod-mediated ecosystem service delivery. We examined the effects of local spatial context (adjacent to woodland or agriculture and irrigation (irrigation or no irrigation on wildflower bloom and visitation by arthropods in a biofeedstocks-wildflower habitat buffer design. Twenty habitat buffer plots were established containing a subplot of Napier grass (Pennisetum perpureum Schumach for biofeedstock, three commercial wildflower mix subplots, and a control subplot containing spontaneous weeds. Arthropods and flowers were visually observed in quadrats throughout the season. At the end of the season we measured soil nutrients and harvested Napier biomass. We found irrespective of buffer location or irrigation, pollinators were observed more frequently early in the season and on experimental plots with wildflowers than on weeds in the control plots. Natural enemies showed a tendency for being more common on plots adjacent to a wooded border, and were also more commonly observed early in the season. Herbivore visits were infrequent and not significantly influenced by experimental treatments. Napier grass yields were high and typical of first-year yields reported regionally, and were not affected by location context or irrigation. Our results suggest habitat management designs integrating bioenergy crop and floral resources provide marketable biomass and habitat for beneficial arthropods.

  1. Variation in sequences containing microsatellite motifs in the perennial biomass and forage grass, Phalaris arundinacea (Poaceae).

    Science.gov (United States)

    Barth, Susanne; Jankowska, Marta Jolanta; Hodkinson, Trevor Roland; Vellani, Tia; Klaas, Manfred

    2016-03-22

    Forty three microsatellite markers were developed for further genetic characterisation of a forage and biomass grass crop, for which genomic resources are currently scarce. The microsatellite markers were developed from a normalized EST-SSR library. All of the 43 markers gave a clear banding pattern on 3% Metaphor agarose gels. Eight selected SSR markers were tested in detail for polymorphism across eleven DNA samples of large geographic distribution across Europe. The new set of 43 SSR markers will help future research to characterise the genetic structure and diversity of Phalaris arundinacea, with a potential to further understand its invasive character in North American wetlands, as well as aid in breeding work for desired biomass and forage traits. P. arundinacea is particularly valued in the northern latitude as a crop with high biomass potential, even more so on marginal lands.

  2. Perennial grasses for recovery of the aggregation capacity of a reconstructed soil in a coal mining area in southern Brazil

    Directory of Open Access Journals (Sweden)

    Lizete Stumpf

    2014-02-01

    Full Text Available The construction of a soil after surface coal mining involves heavy machinery traffic during the topographic regeneration of the area, resulting in compaction of the relocated soil layers. This leads to problems with water infiltration and redistribution along the new profile, causing water erosion and consequently hampering the revegetation of the reconstructed soil. The planting of species useful in the process of soil decompaction is a promising strategy for the recovery of the soil structural quality. This study investigated the influence of different perennial grasses on the recovery of reconstructed soil aggregation in a coal mining area of the Companhia Riograndense de Mineração, located in Candiota-RS, which were planted in September/October 2007. The treatments consisted of planting: T1- Cynodon dactylon cv vaquero; T2 - Urochloa brizantha; T3 - Panicum maximun; T4 - Urochloa humidicola; T5 - Hemarthria altissima; T6 - Cynodon dactylon cv tifton 85. Bare reconstructed soil, adjacent to the experimental area, was used as control treatment (T7 and natural soil adjacent to the mining area covered with native vegetation was used as reference area (T8. Disturbed and undisturbed soil samples were collected in October/2009 (layers 0.00-0.05 and 0.10-0.15 m to determine the percentage of macro- and microaggregates, mean weight diameter (MWD of aggregates, organic matter content, bulk density, and macro- and microporosity. The lower values of macroaggregates and MWD in the surface than in the subsurface layer of the reconstructed soil resulted from the high degree of compaction caused by the traffic of heavy machinery on the clay material. After 24 months, all experimental grass treatments showed improvements in soil aggregation compared to the bare reconstructed soil (control, mainly in the 0.00-0.05 m layer, particularly in the two Urochloa treatments (T2 and T4 and Hemarthria altissima (T5. However, the great differences between the

  3. Complete amino acid sequence of a Lolium perenne (perennial rye grass) pollen allergen, Lol p II.

    Science.gov (United States)

    Ansari, A A; Shenbagamurthi, P; Marsh, D G

    1989-07-05

    The complete amino acid sequence of a Lolium perenne (rye grass) pollen allergen, Lol p II was determined by automated Edman degradation of the protein and selected fragments. Cleavage of the protein by enzymatic and chemical techniques established an unambiguous sequence for the protein. Lol p II contains 97 amino acid residues, with a calculated molecular weight of 10,882. The protein lacks cysteine and glutamine and shows no evidence of glycosylation. Theoretical predictions by Fraga's (Fraga, S. (1982) Can. J. Chem. 60, 2606-2610) and Hopp and Woods' (Hopp, T. P., and Woods, K. R. (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 3824-3828) methods indicate the presence of four hydrophilic regions, which may contribute to sequential or parts of conformational B-cell epitopes. Analysis of amphipathic regions by Berzofsky's method indicates the presence of a highly amphipathic region, which may contain, or contribute to, an Ia/T-cell epitope. This latter segment of Lol p II was found to be highly homologous with an antibody-binding segment of the major rye allergen Lol p I and may explain why immune responsiveness to both the allergens is associated with HLA-DR3.

  4. An experimental analysis of grasshopper community responses to fire and livestock grazing in a northern mixed-grass prairie.

    Science.gov (United States)

    Branson, David H; Sword, Gregory A

    2010-10-01

    The outcomes of grasshopper responses to both vertebrate grazing and fire vary across grassland ecosystems, and are strongly influenced by local climactic factors. Thus, the possible application of grazing and fire as components of an ecologically based grasshopper management strategy must be investigated in regional studies. In this study, we examined the effects of grazing and fire on grasshopper population density and community composition in a northern Great Plains mixed-grass prairie. We employed a large-scale, replicated, and fully-factorial manipulative experimental design across 4 yr to examine the separate and interactive effects of three grazing systems in burned and unburned habitats. Grasshopper densities were low throughout the 4-yr study and 1 yr of pretreatment sampling. There was a significant fire by grazing interaction effect on cumulative density and community composition, resulting from burned season long grazing pastures having higher densities than unburned pastures. Shannon diversity and grasshopper species richness were significantly higher with twice-over rotational livestock grazing. The ability to draw strong conclusions regarding the nature of species composition shifts and population changes in the presence of fire and grazing is complicated by the large site differences and low grasshopper densities. The results reinforce the importance of long-term research to examine the effects of habitat manipulation on grasshopper population dynamics.

  5. Soil modification by invasive plants: Effects on native and invasive species of mixed-grass prairies

    Science.gov (United States)

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2008-01-01

    Invasive plants are capable of modifying attributes of soil to facilitate further invasion by conspecifics and other invasive species. We assessed this capability in three important plant invaders of grasslands in the Great Plains region of North America: leafy spurge (Euphorbia esula), smooth brome (Bromus inermis) and crested wheatgrass (Agropyron cristatum). In a glasshouse, these three invasives or a group of native species were grown separately through three cycles of growth and soil conditioning in both steam-pasteurized and non-pasteurized soils, after which we assessed seedling growth in these soils. Two of the three invasive species, Bromus and Agropyron, exhibited significant self-facilitation via soil modification. Bromus and Agropyron also had significant facilitative effects on other invasives via soil modification, while Euphorbia had significant antagonistic effects on the other invasives. Both Agropyron and Euphorbia consistently suppressed growth of two of three native forbs, while three native grasses were generally less affected. Almost all intra- and interspecific effects of invasive soil conditioning were dependent upon presence of soil biota from field sites where these species were successful invaders. Overall, these results suggest that that invasive modification of soil microbiota can facilitate plant invasion directly or via 'cross-facilitation' of other invasive species, and moreover has potential to impede restoration of native communities after removal of an invasive species. However, certain native species that are relatively insensitive to altered soil biota (as we observed in the case of the forb Linum lewisii and the native grasses), may be valuable as 'nurse'species in restoration efforts. ?? 2007 Springer Science+Business Media B.V.

  6. Alien plant invasion in mixed-grass prairie: effects of vegetation type, stochiasticity, and anthropogenic disturbance in two park units

    Science.gov (United States)

    Larson, Diane L.; Anderson, Patrick J.; Newton, Wesley E.

    2001-01-01

    The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of

  7. Effect of pre-grazing herbage mass on dairy cow performance, grass dry matter production and output from perennial ryegrass (Lolium perenne L.) pastures.

    Science.gov (United States)

    Wims, C M; Delaby, L; Boland, T M; O'Donovan, M

    2014-01-01

    A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumulation under grazing was lowest (Ppastures required more grass silage supplementation during the grazing season (+73 kg DM/cow) to overcome pasture deficits due to lower pasture growth rates (Ppasture intake, although cows grazing the L pastures had to graze a greater daily area (Ppasture reduces pasture DM production and at a system level may increase the requirement for imported feed.

  8. Use of vegetation sampling and analysis to detect a problem within a portion of a prairie restoration project.

    Science.gov (United States)

    Franson, Raymond; Scholes, Chad; Krabbe, Stephen

    2017-01-02

    In June 2005, the Department of Energy (DOE) began establishing the 60-ha Howell Prairie around the disposal cell at the DOE Weldon Spring Site (WSS). Prairies were historically present in the area of the site. Quantitative Cover sampling was used to quantify Total Cover, Native Grass Cover, Non-Native Grass Cover, Native Forb Cover, Non-Native Forb Cover, Warm Season (C 4 Grass), Cool Season (C 3 Grass), Perennial Cover and Annual Cover, Litter, and Bare Ground. Four permanent vegetation sampling plots were established. The first 4 years of vegetation measurements at Howell Prairie were made during above-average rainfall years on burned and unburned plots. The fifth-year (2012) vegetation measurements were made after below-average rainfall. Five years of results not only document the consistency of the restoration effort in three areas, but also demonstrate deficiencies in Grass Cover in a fourth area. The results are not only useful for Howell Prairie, but will be useful for restoration work throughout the region. Restoration work suffers from a lack of success monitoring and in this case from a lack of available reference areas. Floristic Quality Indices are used to make qualitative comparisons of the site to Konza Prairie sites.

  9. Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

    Science.gov (United States)

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots andConvolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvenseand the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested

  10. The role of ecotypic variation and the environment on biomass and nitrogen in a dominant prairie grass.

    Science.gov (United States)

    Mendola, Meredith L; Baer, Sara G; Johnson, Loretta C; Maricle, Brian R

    2015-09-01

    Knowledge of the relative strength of evolution and the environment on a phenotype is required to predict species responses to environmental change and decide where to source plant material for ecological restoration. This information is critically needed for dominant species that largely determine the productivity of the central U.S. grassland. We established a reciprocal common garden experiment across a longitudinal gradient to test whether ecotypic variation interacts with the environment to affect growth and nitrogen (N) storage in a dominant grass. We predicted plant growth would increase from west to east, corresponding with increasing precipitation, but differentially among ecotypes due to local adaptation in all ecotypes and a greater range of growth response in ecotypes originating from west to east. We quantified aboveground biomass, root biomass, belowground net primary production (BNPP), root C:N ratio, and N storage in roots of three ecotypes of Andropogon gerardii collected from and reciprocally planted in central Kansas, eastern Kansas, and s6uthern Illinois. Only the ecotype from the most mesic region (southern Illinois) exhibited more growth from west to east. There was evidence for local adaptation in the southern Illinois ecotype by means of the local vs. foreign contrast within a site and the home vs. away contrast when growth in southern Illinois was compared to the most distant 'site in central Kansas. Root biomass of the eastern Kansas ecotype was higher at home than at either away site. The ecotype from the driest region, central Kansas, exhibited the least response across the environmental gradient, resulting in a positive relationship between the range of biomass response and precipitation in ecotype region of origin. Across all sites, ecotypes varied in root C:N ratio (highest in the driest-origin ecotype) and N storage in roots (highest in the most mesic-origin ecotype). The low and limited range of biomass, higher C:N ratio of roots

  11. Landscape control of nitrous oxide emissions during the transition from conservation reserve program to perennial grasses for bioenergy

    Science.gov (United States)

    Debasish Saha; Benjamin M. Rau; Jason P. Kaye; Felipe Montes; Paul R. Adler; Armen R. Kemanian

    2016-01-01

    Future liquid fuel demand from renewable sources may, in part, be met by converting the seasonally wet portions of the landscape currently managed for soil and water conservation to perennial energy crops. However, this shift may increase nitrous oxide (N2O) emissions, thus limiting the carbon (C) benefits of energy crops. Particularly high emissions may occur during...

  12. Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2)emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma USA

    Science.gov (United States)

    Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2) emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma, USA J.P.S. Neel USDA ARS, El Reno, OK A reduction in enteric CH4 production in ruminants is associated with improved production effic...

  13. Study of atmospheric stratification influence on pollutants dispersion using a numerical fluid mechanics model. Code-Saturne validation with the Prairie Grass experiment/Study of atmospheric stratification influence on pollutants dispersion using a numerical fluid mechanics software

    International Nuclear Information System (INIS)

    Coulon, Fanny

    2010-09-01

    A validation of Code-Saturne, a computational fluids dynamics model developed by EDF, is proposed for stable conditions. The goal is to guarantee the performance of the model in order to use it for impacts study. A comparison with the Prairie Grass data field experiment and with two Gaussian plume models will be done [fr

  14. Evaluation of Turf-Grass and Prairie-Vegetated Rain Gardens in a Clay and Sand Soil, Madison, Wisconsin, Water Years 2004-08

    Science.gov (United States)

    Selbig, William R.; Balster, Nicholas

    2010-01-01

    The U.S. Geological Survey, in cooperation with a consortium of 19 cities, towns, and villages in Dane County, Wis., undertook a study to compare the capability of rain gardens with different vegetative species and soil types to infiltrate stormwater runoff from the roof of an adjacent structure. Two rain gardens, one planted with turf grass and the other with native prairie species, were constructed side-by-side in 2003 at two locations with different dominant soil types, either sand or clay. Each rain garden was sized to a ratio of approximately 5:1 contributing area to receiving area and to a depth of 0.5 foot. Each rain garden, regardless of vegetation or soil type, was capable of storing and infiltrating most of the runoff over the 5-year study period. Both rain gardens in sand, as well as the prairie rain garden in clay, retained and infiltrated 100 percent of all precipitation and snowmelt events during water years 2004-07. The turf rain garden in clay occasionally had runoff exceed its confining boundaries, but was still able to retain 96 percent of all precipitation and snowmelt events during the same time period. Precipitation intensity and number of antecedent dry days were important variables that influenced when the storage capacity of underlying soils would become saturated, which resulted in pooled water in the rain gardens. Because the rooftop area that drained runoff to each rain garden was approximately five times larger than the area of the rain garden itself, evapotranspiration was a small percentage of the annual water budget. For example, during water year 2005, the maximum evapotranspiration of total influent volume ranged from 21 percent for the turf rain garden in clay to 25 percent for the turf rain garden in sand, and the minimum ranged from 12 percent for the prairie rain garden in clay to 19 percent for the prairie rain garden in sand. Little to no runoff left each rain garden as effluent and a small percentage of runoff returned to the

  15. Native prairie revegetation on wellsites in southeastern Alberta

    International Nuclear Information System (INIS)

    Soulodre, E.; Naeth, A.; Hammermeister, A.

    1999-01-01

    The Native Prairie Revegetation Research Project (NPRRP) was initiated to address concerns about wellsite revegetation of native grassland. The objective was to determine the impact of alternative seeding treatments on soil and vegetation and to produce a quantifiable description of what constitutes successful revegetation of native prairie sites. Four wellsites, each site comprising four revegetation treatment plots and an undisturbed control plot, have been chosen for field study. The revegetation treatments included natural recovery without seeding; current mix dominated by native wheatgrass cultivars; simple mix seeding containing wheatgrasses plus other native grasses, and diverse mix seeding with a mixture of wheatgrasses, other grasses and thirteen perennial forbs. The plant communities were monitored for biomass production, species richness, species composition and a combination of factors which include density, frequency, canopy cover and basal cover, these collectively representing importance value. Nitrogen availability in the soil was also monitored. Results showed high importance values for wheatgrasses for all seeded treatments. Perennial non-wheatgrasses had low importance values in the seeded treatment but higher importance in the control plot. The dominance of wheatgrasses in the seeded treatments resulted in communities that differed significantly from both the control and natural recovery communities, probably due to suppression of the growth of other grasses

  16. Large-scale downy brome treatments alter plant-soil relationships and promote perennial grasses in salt desert shrublands

    Science.gov (United States)

    The interrelationship between invasive annual grass abundance and soil resource availability varies spatially and temporally within ecosystems and may be altered by land treatments. We evaluated these relationships in two salt desert landscapes where the local abundance of Bromus tectorum L. (downy...

  17. The effects of forest residual debris disposal on perennial grass emergence, growth, and survival in a ponderosa pine ecotone

    Science.gov (United States)

    Darin J. Law; Peter F. Kolb

    2007-01-01

    Soil surface conditions can have profound effects on plant seedling emergence and subsequent seedling survival. To test the hypothesis that different soil-surface treatments with logging residue affect range grass seedling emergence and survival, 6 alternative forest-residual treatments were established in the summer of 1998 following thinning of mature trees from...

  18. The Study of Perennial Grasses and Legumes Mixtures in the Environmental Conditions Part 1: The Evolution of Mixtures Productivity from Someşelor Plateau

    Directory of Open Access Journals (Sweden)

    Dorin-Benone Pleşa

    2012-05-01

    Full Text Available Lately it is a high interest in the establishing of temporary grasslands, these being considered a valuable source of fodder from the quantitative and qualitative point of view. Temporary grasslands can be established instead of degraded permanent grasslands or in arable lands. In the paper are presented the results of the research which took place in 2010 and 2011, regarding the fodder evolution of a double factor experience; A factor – mixtures (8 complex mixtures of perennial grasses and legumes and one alfalfa pure crop, considered as a witness,B factor – levels of fertilization (0N0P2O5, 60N70P2O5,120N70P2O5 kg·ha-1. In 2010 the highest productions (13.16 SU t·ha-1 were obtained at all the cycles from the 5th mixture composed from red clover and 4 species of grasses Trifolium pratense L., Dactylis glomerata L., Festulolium Asch. & Graebn., Phleum pratense L., Lolium perenne L.. In 2011, mixture number 3, recognized as being recommended for the forest steppe area and composed from Lotus corniculatus L.,Onobrychis viciifolia Scop., Dactylis glomerata L., Festuca pratensis Huds., Bromus inermis Leyss, presented the highest productions (4.82 t·ha-1 for the 60N70P2O5 and 120N70P2O5 kg·ha-1 levels of fertilization.

  19. Fire and nitrogen effects on Purple Threeawn (Aristida purpurea)abundance in northern mixed-grass prairie old fields

    Science.gov (United States)

    Purple threeawn (Aristida purpurea Nutt. varieties) is a native grass capable of increasing on rangelands, forming near monocultures, and creating a stable state. Productive rangelands throughout the Great Plains and Intermountain West have experienced increases in purple threeawn abundance, reduci...

  20. Effects of vesicular-arbuscular mycorrhizae on survival and growth of perennial grasses in lignite overburden in Texas

    Energy Technology Data Exchange (ETDEWEB)

    Call, C.A.; Davies, F.T.

    1988-12-01

    Seedlings of sideoats grama (Bouteloua curtipendula), Indiangrass (Sorghastrum nutans), and kleingrass (Panicum coloratum) were inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi (Glomus fasciculatum and Gigaspora margarita) in a containerized system and transplanted into lignite overburden in the Post Oak Savannah region of Texas, U.S.A. After three growing seasons without cultural inputs, plants inoculated with VAM fungi had greater survival percentages, basal diameters, and above-ground biomass than noninoculated plants. Inoculated plants had higher levels of nitrogen and phosphorus in above-ground biomass than noninoculated plants. Root colonization percentages of inoculated plants remained fairly stable while noninoculated plants showed low levels of colonization over the 3-year study period. Vesicular-arbuscular mycorrhizae enhanced the survival and growth of the 3 grass species by making effective use of limited resources in the lignite overburden. 31 refs., 3 tabs.

  1. Establishment, Growth, and Yield Potential of the Perennial Grass Miscanthus × Giganteus on Degraded Coal Mine Soils

    Directory of Open Access Journals (Sweden)

    Stanisław Jeżowski

    2017-06-01

    Full Text Available Miscanthus × giganteus is a giant C4 grass native to Asia. Unlike most C4 species, it is relatively cold tolerant due to adaptations across a wide range of altitudes. These grasses are characterized by high productivity and low input requirements, making them excellent candidates for bioenergy feedstock production. The aim of this study was to investigate the potential for growing Miscanthus on extremely marginal soils, degraded by open lignite (brown coal mining. Field experiments were established within three blocks situated on waste heaps originating from the lignite mine. Analyses were conducted over the first 3 years following Miscanthus cultivation, focusing on the effect of organic and mineral fertilization on crop growth, development and yield in this extreme environment. The following levels of fertilization were implemented between the blocks: the control plot with no fertilization (D0, a plot with sewage sludge (D1, a plot with an identical amount of sewage sludge plus one dose of mineral fertilizer (D2 and a plot with an identical amount of sewage sludge plus a double dose of mineral fertilizer (D3. Crop development and characteristics (plant height, tillering, and biomass yield [dry matter] were measured throughout the study period and analyzed using Analysis of Variance (ANOVA. Significant differences were apparent between plant development and 3rd year biomass production over the course of the study (0.964 kg plant-1 for DO compared to 1.503 kg plant-1 for D1. Soil analyses conducted over the course of the experiment showed that organic carbon levels within the soil increased significantly following the cultivation of Miscanthus, and overall, pH decreased. With the exception of iron, macronutrient concentrations remained stable throughout. The promising yields and positive effects of Miscanthus on the degraded soil suggests that long term plantations on land otherwise unsuitable for agriculture may prove to be of great

  2. Pyrolysis and kinetic analyses of a perennial grass (Saccharum ravannae L.) from north-east India: Optimization through response surface methodology and product characterization.

    Science.gov (United States)

    Saikia, Ruprekha; Baruah, Bhargav; Kalita, Dipankar; Pant, Kamal K; Gogoi, Nirmali; Kataki, Rupam

    2018-04-01

    The objective of the present investigation was to optimize the pyrolysis condition of an abundantly available and low cost perennial grass of north-east India Saccharum ravannae L. (S. ravannae) using response surface methodology based on central composite design. Kinetic study of the biomass was conducted at four different heating rates of 10, 20, 40 and 60 °C min -1 and results were interpreted by Friedman, Kissinger Akira Sunnose and Flynn-Wall-Ozawa methods. Average activation energy 151.45 kJ mol -1 was used for evaluation of reaction mechanism following Criado master plot. Maximum bio-oil yield of 38.1 wt% was obtained at pyrolysis temperature of 550 °C, heating rate of 20 °C min -1 and nitrogen flow rate of 226 mL min -1 . Study on bio-oil quality revealed higher content of hydrocarbon, antioxidant property, total phenolic content and metal chelating capacity. These opened up probable applications of S. ravannae bio-oil in different fields including fuel, food industry and biomedical domain. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Effects of Altered Seasonality of Precipitation on Grass Production and Grasshopper Performance in a Northern Mixed Prairie.

    Science.gov (United States)

    Branson, David H

    2017-06-01

    Climatic changes are leading to differing patterns and timing of precipitation in grassland ecosystems, with the seasonal timing of precipitation affecting plant biomass and plant composition. No previous studies have examined how drought seasonality affects grasshopper performance and the impact of herbivory on vegetation. We modified seasonal patterns of precipitation and grasshopper density in a manipulative experiment to examine if seasonality of drought combined with herbivory affected plant biomass, nitrogen content, and grasshopper performance. Grass biomass was affected by both precipitation and grasshopper density treatments, while nitrogen content of grass was higher with early-season drought. Proportional survival was negatively affected by initial density, while survival was higher with early drought than with full-season drought. Drought timing affected the outcome, with early summer drought increasing grass nitrogen content and grasshopper survival, while season-long and late-season drought did not. The results support arguments that our knowledge of plant responses to seasonal short-term variation in climate is limited and illustrate the importance of experiments manipulating precipitation phenology. The results confirm that understanding the season of drought is critical for predicting grasshopper population dynamics, as extreme early summer drought may be required to strongly affect Melanoplus sanguinipes (F.) performance. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  4. Evaluation of the greenhouse effect gases (CO{sub 2}, CH{sub 4}, N{sub 2}O) in grass land and in the grass breeding. Greenhouse effect gases prairies. report of the first part of the project December 2002; Bilan des emissions de gaz a effet de serre (CO{sub 2}, CH{sub 4}, N{sub 2}O) en prairie paturee et dans des exploitations d'elevage herbager. GES-Prairies. Rapport de la premiere tranche du projet Decembre 2002

    Energy Technology Data Exchange (ETDEWEB)

    Soussana, J.F

    2002-12-15

    In the framework of the Kyoto protocol on the greenhouse effect gases reduction, many ecosystems as the prairies can play a main role for the carbon sequestration in soils. The conservation of french prairies and their management adaptation could allow the possibility of carbon sequestration in the soils but also could generate emissions of CO{sub 2} and CH{sub 4} (by the breeding animals on grass) and N{sub 2}O (by the soils). This project aims to establish a detailed evaluation of the contribution of the french prairies to the the greenhouse effect gases flux and evaluate the possibilities of reduction of the emissions by adaptation of breeding systems. (A.L.B.)

  5. Greenhouse gas flux under warm-season perennial C4 grasses across different soil and climate gradients on the Islands of Hawaii

    Science.gov (United States)

    Pawlowski, M. N.; Crow, S. E.; Sumiyoshi, Y.; Wells, J.; Kikkawa, H. R.

    2011-12-01

    Agricultural soils can serve as either a sink or a source for atmospheric carbon (C) and other greenhouse gases (GHG). This is particularly true for tropical soils where influences from climate and soil gradients are wide ranging. Current estimates of GHG flux from soil are often under or overestimated due to high variability in sample sites and inconsistencies in land use and vegetation type, making extrapolation to new study systems difficult. This work aimed to identify patterns of trace fluxes of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) across two soil types and three species of warm season perennial C4 grasses: Pennisetum purpureum (Napier grass), Panicum maximum (Guinea grass) and Saccharum officinarum (sugar cane) on the islands of Oahu and Maui in Hawaii. Multiple static vented chambers were installed into replicate plots for each species; flux measurements were made during the growth, fertilization and harvest cycles at set time intervals for one hour and analyzed by gas chromatography. Initial results from Oahu indicate no significant differences in CO2 flux between the P. maximum and P. purpureum species after fertilization or at full growth. We observed an average flux of 143 mg m-2 h-1 and 155 mg m-2 h-1 for P. maximum and P. purpureum respectively at full growth for CO2 and 1.7 μg m-2 h-1and 0.3 μg m-2 h-1 for N2O. Additionally, N2O rates sampled after a typical fertilizer application were significantly greater than at full growth (p=0.0005) with flux rates of 25.2 μg m2h-1 and 30.3 μg m2h-1 for P. maximum and P. purpureum respectively. With a global warming potential of 310 for N2O, even short-term spikes following fertilizer application can cause long lasting effects of GHG emission from agricultural soils. CH4 flux was negligible for all species on the Oahu plots during these sample periods. Globally, water limitation is a major factor influencing the potential productivity of agricultural crops and the sustainability of

  6. The effects of black-tailed prairie dogs on plant communities within a complex urban landscape: an ecological surprise?

    Science.gov (United States)

    Beals, Stower C; Hartley, Laurel M; Prevéy, Janet S; Seastedt, Timothy R

    2014-05-01

    Historically, prairie dogs (Cynomys spp.) have been considered essential keystone species of western United States grassland ecosystems because they provide unique services and increase vegetation community richness, evenness, and diversity. However, the effects of black-tailed prairie dogs (Cynomys ludovicianus) on lands adjacent to or surrounded by urban areas may not result in the same ecosystem benefits historically associated with their presence. An urban landscape presents prairie dogs with movement challenges unparalleled in natural landscapes, as well as suites of nonnative plant species that are more common in disturbed areas. This study examined a complex ecosystem where vegetation communities are being influenced by directional environmental change, and quantified the synergistic effects resulting from the protective management of a native keystone species. The data set for this analysis was comprised of 71 paired (occupied by prairie dogs vs. unoccupied) vegetation surveys and 156 additional unpaired surveys collected from around the city of Boulder, Colorado, USA for 14 yr. Linear mixed models were used to compare data from transects occupied and unoccupied by prairie dogs, as well as to evaluate the effect of prairie dog occupation duration. In the absence of prairie dogs, vegetation in this region exhibited declines in native grasses, no changes in introduced grasses, and increases in native and nonnative forbs and bare soil over the study interval. In the presence of prairie dogs, these observed directional changes were nearly all amplified at rates four to 10 times greater than when prairie dogs were absent. Areas in Boulder occupied by prairie dogs also had significantly lower richness, evenness, and diversity of plant species, compared to unoccupied areas. Analysis of plant functional groups revealed the significant reduction of perennial native grasses, as well as a significantly higher cover of introduced forbs in occupied areas. Prairie dogs

  7. Use of ecological sites in managing wildlife and livestock: An example with prairie dogs

    Science.gov (United States)

    Prairie dogs are a native rodent found in the mixed grass prairie of the northern Great Plains. Prairie dogs can have an adverse impact on the amount of forages available for grazing livestock. In the Native American community, prairie dogs are often valued as a cultural resource and as an importan...

  8. Annual maize and perennial grass-clover strip cropping for increased resource use efficiency and productivity using organic farming practice as a model

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Johansen, Anders; Carter, Mette Sustmann

    2013-01-01

    A cropping system was designed to fulfill the increasing demand for biomass for food and energy without decreasing long term soil fertility. A field experiment was carried out including alternating strips of annual maize (Zea mays L.) and perennial ryegrass (Lolium perenne L.) – clover (Trifolium...

  9. Sound transmission at ground level in a short-grass prairie habitat and its implications for long-range communication in the swift fox Vulpes velox

    DEFF Research Database (Denmark)

    Darden, Safi K; Pedersen, Simon B; Larsen, Ole N

    2008-01-01

    The acoustic environment of swift foxes Vulpes velox vocalizing close to the ground and the effect of propagation on individual identity information in vocalizations were quantified in a transmission experiment in prairie habitat. Sounds were propagated (0.45 m above the ground) at distances up t...

  10. Water use, root activity and deep drainage within a perennial legume-grass pasture: A case study in southern inland Queensland, Australia

    Directory of Open Access Journals (Sweden)

    A. Nahuel A. Pachas

    2016-09-01

    Full Text Available Water use and depth of water extraction of leucaena (Leucaena leucocephala and Rhodes grass (Chloris gayana pasture, irrigated with desalinated coal seam water (a by-product of the coal seam gas industry, were monitored to provide background information on root activity, spatial and temporal water use and deep drainage over a 757-day period from August 2011 to August 2013. Methodology comprised measurement of soil water from surface to 4 m depth using 8 EnviroSCAN probes connected to dataloggers positioned within leucaena twin rows and within the Rhodes grass inter-row. Just over 581,000 individual moisture measurements were collated and are reported here. Water extraction (and by inference root activity of leucaena and Rhodes grass showed marked seasonal fluctuation with deepest and highest water extraction occurring during the first growing season; water extraction was greatly diminished during the following drier and cooler seasons due to the negative influences of lower soil moisture contents, lower temperatures and increased defoliation on pasture growth. The highest values of deep drainage below 4 m depth occurred when high rainfall events corresponded with high soil water storage in the entire profile (0–4 m depth. Given that water usage by both leucaena and Rhodes grass was greatest in the upper layers of soil (<1.5 m, future research should focus on how the level of competitive interaction might be managed by choice of row spacing and frequency of irrigation. Further studies are needed, including: (a physical sampling to determine the depth of active roots; (b how defoliation affects rooting behaviours and water use of leucaena; and (c modelling of the water and salt balances of leucaena and grass inter-row systems using data from this study, with various levels of irrigation, to investigate the risks of deep drainage over an extended climate sequence.Keywords: Active rooting depth, agroforestry, Chloris gayana, Leucaena leucocephala

  11. Phenotypic and genetic characterization of wildland collections of western and Searls prairie clovers for rangeland revegetation in the western USA

    Science.gov (United States)

    Kishor Bhattarai

    2010-01-01

    Western prairie clover [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright] is a perennial legume that occurs in the northern Great Basin, Snake River Basin, and southern Columbia Plateau, whereas Searls prairie clover [Dalea searlsiae (A. Gray) Barneby], also a perennial legume, occurs in the southern Great Basin and surrounding areas. Understanding the genetic and...

  12. Prairie Chicken

    Data.gov (United States)

    Kansas Data Access and Support Center — An outline of the general range occupied by greayter and lesser prairie chickens. The range was delineated by expert opinion, then varified by local wildlife...

  13. Establishment of prairies

    International Nuclear Information System (INIS)

    Lotero Cadavid, J.

    2001-01-01

    Are analyzed the establishment of prairies, such as the selection of the species, the factors of the environment, the impact in the establishment and forage production and its relation to the soil, the precipitation, the temperature, the light and the biotic factors. It is indicated that the selection of the species to settle down, is directly related with the climate and the soil and they group to be tolerant to drought, tolerant to flood soils, tolerant to humid soils, tolerant to soils very acids, moderately acids and saline. It is noticed that a bad establishment of the grasses can be due to the bad quality of the seed, a temperature and unfavorable humidity can cause low germination; equally seeds planted very deeply in heavy soils with excess of humidity. Considerations are made about the establishment and growth of the prairies in connection with the germination, cultures, sowing density and sowing on time, as well as for the soil preparation, the sowing in terrestrial mechanic and non mechanic and the use of cultivations forms of low cost and fertilization systems; equally the establishment of leguminous in mixture with gramineous, the renovation of prairies and the establishment of pastures

  14. The effect of reciprocal treatments with ozone and ultraviolet-B radiation on photosynthesis and growth of perennial grass Elymus athericus

    International Nuclear Information System (INIS)

    Staaij, J.W.M. van de; Tonneijck, A.E.G.; Rozema, J.

    1997-01-01

    The impact on plant growth of the simultaneously changing factors of the global climate, rising tropospheric O 3 concentrations and increasing UV-B radiation fluxes, has been tested in a combined glasshouse and growth chamber experiment. The saltmarsh grass species Elymus athericus was sequentially fumigated for two weeks with O 3 and for another two weeks irradiated with UV-B (vv). Exposure to elevated UV-B did not negatively affect photosynthesis or plant growth. Fumigation with O 3 had a depressing effect on net photosynthesis, the number and biomass of flowers, the number of leaves and the number of shoots. O 3 -induced damage only was observed in plants which had been fumigated during the last two weeks of the experiment. Since interactive responses were not observed, results suggest different primary target sites for O 3 and UV-B within the plant

  15. Power and limitation of soil properties as predictors of rangeland health and ecosystem functioning in a Northern mixed-grass prairie[Abstract

    Science.gov (United States)

    Soil properties are thought to affect rangeland ecosystem functioning (e.g. primary productivity, hydrology), and thus soil variables that are consistently correlated with key ecosystem functions may be general indicators of rangeland health. We summarize results from several studies in mixed-grass...

  16. Carbon storage potential increases with increasing ratio of C4 to C3 grass cover and soil productivity in restored tallgrass prairies.

    Science.gov (United States)

    Spiesman, Brian J; Kummel, Herika; Jackson, Randall D

    2018-02-01

    Long-term soil carbon (C) storage is essential for reducing CO 2 in the atmosphere. Converting unproductive and environmentally sensitive agricultural lands to grasslands for bioenergy production may enhance C storage. However, a better understanding of the interacting effects of grass functional composition (i.e., relative abundance of C 4 and C 3 grass cover) and soil productivity on C storage will help guide sustainable grassland management. Our objective was to examine the relationship between grass functional composition and potential C storage and how it varies with potential soil productivity. We estimated C inputs from above- and belowground net primary productivity (ANPP and BNPP), and heterotrophic respiration (R H ) to calculate net ecosystem production (NEP), a measure of potential soil C storage, in grassland plots of relatively high- and low-productivity soils spanning a gradient in the ratio of C 4 to C 3 grass cover (C 4 :C 3 ). NEP increased with increasing C 4 :C 3 , but only in potentially productive soils. The positive relationship likely stemmed from increased ANPP, rather than BNPP, which was possibly related to efficient resource-use and physiological/anatomical advantages of C 4 plants. R H was negatively correlated with C 4 :C 3 , possibly because of changes in microclimate or plant-microbe interactions. It is possible that in potentially productive soils, C storage can be enhanced by favoring C 4 over C 3 grasses through increased ANPP and BNPP and reduced R H . Results also suggest that potential C storage gains from C 4 productivity would not be undermined by a corresponding increase in R H .

  17. NPP Grassland: Konza Prairie, USA, 1984-1990, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains three ASCII files (.txt format). Two files contain above-ground biomass and productivity data for a humid temperate tall-grass prairie...

  18. Complete primary structure of a Lolium perenne (perennial rye grass) pollen allergen, Lol p III: comparison with known Lol p I and II sequences.

    Science.gov (United States)

    Ansari, A A; Shenbagamurthi, P; Marsh, D G

    1989-10-17

    The complete amino acid sequence of a Lolium perenne (rye grass) pollen allergen, Lol p III, determined by the automated Edman degradation of the protein and its selected fragments, is reported in this paper. Cleavage by enzymatic and chemical techniques established unambiguously the sequence for this 97-residue protein (Mr = 10,909), which lacks cysteine and shows no evidence of glycosylation. The sequence of Lol p III is very similar to that of another L. perenne allergen, Lol p II, which was sequenced recently; of the 97 positions in the two proteins, 57 are occupied by identical amino acids (59% identity). In addition, both allergens share a similar structure with an antibody-binding fragment of a third L. perenne allergen, Lol p I. Since human antibody responsiveness to all these three allergens is associated with HLA-DR3, and since the structure common to the three molecules shows high degrees of amphipathicity in Lol p II and III, we speculate that this common segment in the three molecules might contain or contribute to the respectively Ia/T-cell sites.

  19. Plantio direto de alface adubada com cama de aviário sobre coberturas vivas de grama e amendoim forrageiro Lettuce cultivated directly in poultry manure beds using grass and perennial peanut as living mulch

    Directory of Open Access Journals (Sweden)

    Nelson Geraldo de Oliveira

    2006-03-01

    Full Text Available A viabilidade agronômica do plantio direto de alface cv. Vera foi avaliada sobre coberturas vivas perenes de gramínea e leguminosa em sistema de manejo orgânico. Empregou-se o delineamento de blocos casualizados, dispostos em parcelas sub-divididas. Os tratamentos nas parcelas constaram de plantio em sistema de preparo convencional do solo (controle, plantio direto sobre cobertura viva de grama batatais e plantio direto sobre cobertura viva de amendoim forrageiro. Os tratamentos nas subparcelas constaram de adubação com doses de cama de aviário aplicada em cobertura (0; 7; 14 e 28 t ha-1, parceladas em três épocas. Observou-se que a produção de cabeça de alface não foi influenciada pelo modo de plantio e nem pela espécie de cobertura viva sobre a qual foi realizado o plantio direto. Modelo quadrático mostrou-se adequado para descrever a variação observada dos valores de produção de cabeça de alface em relação a doses. O rendimento máximo estimado pelo modelo de regressão para a massa fresca média de alface foi de 348 g planta-1 para a dose de 23 t ha-1 de cama de aviário. O plantio direto de alface sobre cobertura viva de grama batatais e amendoim forrageiro acarretou desempenho semelhante ao desta hortaliça, em sistema de preparo convencional do solo, com nível máximo de produtividade de 55,99 t ha-1 de massa fresca estimado pelo modelo de regressão.The agronomic viability of no-tillage system for lettuce was evaluated, using grass and legume as cover crop under organic management. A randomized complete block design with split plot arrangement was used. Plot treatments were conventional soil tillage (control, bahia grass and perennial peanut cultivated for living cover crops on no-tillage system. Split-plot treatments were doses of poultry manure (0; 7; 14 and 28 t ha-1 in three application periods. Lettuce cv. Vera yield was not affected by tillage system neither by cover crop. The quadratic model was the most

  20. Land use history, ecosystem type and species composition drive water use efficiency in annual maize and perennial grasslands in a humid temperate climate

    Science.gov (United States)

    Gelfand, I.; Abraha, M.; Chen, J.; Shao, C.; Su, Y. J.; Hamilton, S. K.; Robertson, G. P.

    2015-12-01

    Water use efficiency (WUE), carbon gained per unit water lost, is a fundamental plant and ecosystem function that regulates plant productivity, global hydrology and carbon cycles. We examined ecosystem (E) and intrinsic (i) WUEs derived from eddy covariance (EC) measurements and plant carbon isotope discrimination, respectively, to study how WUE is affected by land-use history, ecosystem type, and plants community composition. We measured EWUE and iWUE of three perennial grasslands planted to mixed-prairie, switchgrass and brome grass as compared to a fields planted to corn. Each of studied ecosystems was replicated on two fields with contrasting land-use histories: one field was managed under the USDA Conservation Reserve Program (CRP, planted to bromgrass) and another was in conventional agriculture (AGR) corn/soybean rotation for few decades before start of the experiment. In 2009, all but one CRP field were converted to no-till soybean. In 2010, the converted CRP and AGR fields were planted to mixed-prairie (C3 and C4 grasses), switchgrass (C4 grass), and no-till corn (C4 grass). During 2009-2013, we measured carbon and water exchange over each field using an EC technique and sampled plant tissue for 13C isotopes analysis. Land-use history, ecosystem type, and species composition had large effects on EWUEs. Intrinsic WUE of individual C3 grass species, however, was similar across the study period, despite drought in 2012. Corn and brome grass had the highest and lowest overall mean EWUE, 4.1 and 2.2 g C kg-1 H2O, respectively. Restored prairie on former AGR land had a mean EWUE of 3.0 g C kg-1 H2O, significantly greater than on former CRP land with a EWUE of 2.5 g C kg-1 H2O. Land use history had no effect on interannual variability of EWUE of corn. Prairie and switchgrass established on former CRP land exhibited no change of EWUE, as well. Same ecosystems established on former AGR land, oppositely, increased their WUEs over the study period from ~ 2.5 g C kg-1

  1. Prairie revegetation of a strip mine in Illinois: fifteen years after establishment

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, E.A.; Anderson, R.C.; Rodgers, C.S. [Illinois State University, Normal, IL (United States). Dept. of Biological Sciences

    1996-12-01

    The long-term success of prairie planting on a former strip mine in northeastern Illinois was investigated. The site was reclaimed and planted with prairie species in the 1970s. Total biomass increased over time, largely as a result of an increase in biomass of non-prairie species. Biomass of prairie species remained unchanged because of an increase in Panicum virgatum (switchgrass) offsetting decreases in Sorghastrum nutans (Indian grass).

  2. Perennial grasses traits as functional markers of grazing intensity in basaltic grasslands of Uruguay Rasgos de gramíneas perennes como marcadores funcionales de la intensidad de pastoreo en pastizales de basalto en Uruguay

    Directory of Open Access Journals (Sweden)

    Martin Jaurena

    2012-12-01

    Full Text Available Natural grasslands in the basaltic region of Uruguay are threatened by an increase in stocking rates and changes in land use. To assess the effect of grazing intensification, plant functional types are proposed as simple tools to aid the monitoring and management of vegetation. In the present study we evaluated the effect of stocking rate increase at community level taking into account plant traits of 23 dominant perennial grass species. In order to identify plant functional types, we determined the grazing response in an experiment with two wethers stocking rates (0.78 and 1.56 livestock units ha-1 quantifying species cover and traits values. Leaf dry matter content (LDMC and specific leaf area (SLA were the traits that best described the perennial grasses response to the stocking rate increase and therefore are suggested to be used as functional markers. Three functional types were identified. Low stocking rates were related to functional type A (tall, warm season species with low SLA and high LDMC and functional type B (tall, cool-season species, with intermediate levels of leaf traits. On the other hand, high stocking rate encouraged functional type C (prostrate, warm season species, with high SLA and low LDMC. The classification of a highly diverse community into three functional types and the selection of traits as functional markers candidates is an innovative approach to develop simple and general methods to diagnosis the state of basaltic grasslands in Uruguay and to advise on its management.Las praderas naturales de la region bas áltica de Uruguay están amenazadas por el incremento de la carga animal y cambios en el uso del suelo. Para evaluar el efecto del pastoreo se han propuesto los grupos funcionales como una herramienta simple para el monitoreo y manejo de la vegetación. El presente estudio evaluó el efecto del incremento de la carga animal considerando rasgos de 23 especies de gramineas perennes dominantes. Para identificar

  3. Influence of richness and seeding density on invasion resistance in experimental tallgrass prairie restorations

    Science.gov (United States)

    Nemec, Kristine T.; Allen, Craig R.; Helzer, Christopher J.; Wedin, David A.

    2013-01-01

    In recent years, agricultural producers and non-governmental organizations and agencies have restored thousands of hectares of cropland to grassland in the Great Plains of the United States. However, little is known about the relationships between richness and seeding density in these restorations and resistance to invasive plant species. We assessed the effects of richness and seeding density on resistance to invasive and other unseeded plant species in experimental tallgrass prairie plots in central Nebraska. In 2006, twenty-four 55 m × 55 m plots were planted with six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Conservation Reserve Program mix, CP25), at low and high seeding densities. There was a significant negative relationship between richness and basal cover of unseeded perennial forbs/legumes and unseeded perennial/annual grasses, abundance of bull thistle (Cirsium vulgare), and the number of inflorescences removed from smooth brome (Bromus inermis) transplants. Invasion resistance may have been higher in the high richness treatments because of the characteristics of the dominant species in these plots or because of greater interspecific competition for limiting resources among forbs/legumes with neighboring plants belonging to the same functional group. Seeding density was not important in affecting invasion resistance, except in the cover of unseeded grasses. Increasing seed mix richness may be more effective than increasing the seeding density for decreasing invasion by unseeded perennial species, bull thistle, and smooth brome.

  4. Brant Prairie : Union Gas customer service centre, Brantford, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Hensel, M.J.; Thompson, J. [The Walter Fedy Partnership, Kitchener, ON (Canada)

    1998-12-31

    The four-acre ecological restoration of tall grass prairie, wetland and Savannah ecosystems within the Union Gas Customer Service Centre in Brantford, Ontario is discussed. The restoration of the Brant Prairie site was instigated three years ago through Union Gas` land stewardship and environmental action initiative which tried to encourage the diversity and dynamics of each ecosystem, while creating a community resource for visitors to learn about natural heritage. The Brantford initiative includes: (1) protecting the sedge wetland which contained regionally rare species, (2) maintaining the dynamic water budget while protecting the sedge wetland from roadway contaminants, (3) creating a tall grass prairie similar in diversity and aesthetics to Brantford`s surviving prairie remnants, (4) creating a wildlife habitat for butterflies, birds and aquatic species, and (5) rediscovering partridge pea by uncovering a historic seed bank.

  5. Plant composition in oak savanna and woodland restoration at Prairie Fork Conservation Area in Missouri

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; J.W. Van Sambeek; Jamie Coe; Warren Taylor

    2007-01-01

    The wooded areas of the Prairie Fork Conservation Area in central Missouri are typical of the oak/hickory forest/prairie transition zone that will require active management to restore pre-settlement, grass dominated savannas and open woodlands to improve habitat for wildlife. We initiated a management program to restore savannas and woodlands by reducing the midstory (...

  6. Establishment techniques in under-sown perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Deleuran, Lise C; Boelt, Birte

    2009-01-01

    Establishment methods have proven to be of major importance for grass-seed production. The objective of this research was to test the effect of different sowing techniques on plant establishment and the subsequent seed yield. Perennial ryegrass (Lolium perenne L.) is used as the model grass due...... to its large importance in Danish agriculture. In a three-year trial six different methods of under-sowing of perennial ryegrass in a spring barley cover crop were employed. Perennial ryegrass was either sown directly at different depths within the spring barley (Hordeum vulgare L.) rows or placed 2, 6......, or 12 cm from the spring barley rows. Results of dry-matter yield indicate that the best establishment of the grass occurred when placing the grass 6 or 12 cm from the cover-crop row, and this is of importance in less vigorous grasses. Overall, no seed-yield difference has been observed for perennial...

  7. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion.

    Science.gov (United States)

    Zhou, Xiaobo; Helmers, Matthew J; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D

    2010-01-01

    Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3-N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20 PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)--soybean [Glycine max. (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3-N concentration from 2005 to 2008. The results indicated significant increases in NO3-N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.

  8. Prairie Monitoring Protocol Development: North Coast and Cascades Network

    Science.gov (United States)

    McCoy, Allen; Dalby, Craig

    2009-01-01

    The purpose of the project was to conduct research that will guide development of a standard approach to monitoring several components of prairies within the North Coast and Cascades Network (NCCN) parks. Prairies are an important element of the natural environment at many parks, including San Juan Island National Historical Park (NHP) and Ebey's Landing National Historical Reserve (NHR). Forests have been encroaching on these prairies for many years, and so monitoring of the prairies is an important resource issue. This project specifically focused on San Juan Island NHP. Prairies at Ebey's Landing NHR will be monitored in the future, but that park was not mapped as part of this prototype project. In the interest of efficiency, the Network decided to investigate two main issues before launching a full protocol development effort: (1) the imagery requirements for monitoring prairie components, and (2) the effectiveness of software to assist in extracting features from the imagery. Several components of prairie monitoring were initially identified as being easily tracked using aerial imagery. These components included prairie/forest edge, broad prairie composition (for example, shrubs, scattered trees), and internal exclusions (for example, shrubs, bare ground). In addition, we believed that it might be possible to distinguish different grasses in the prairies if the imagery were of high enough resolution. Although the areas in question at San Juan Island NHP are small enough that mapping on the ground with GPS (Global Positioning System) would be feasible, other applications could benefit from aerial image acquisition on a regular, recurring basis and thereby make the investment in aerial imagery worthwhile. The additional expense of orthorectifying the imagery also was determined to be cost-effective.

  9. Feijão-vagem semeado sobre cobertura viva perene de gramínea e leguminosa e em solo mobilizado, com adubação orgânica Snap bean planted on living perennial mulch of grass and legume and in tilled soil with organic amendment

    Directory of Open Access Journals (Sweden)

    Nelson Geraldo de Oliveira

    2006-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o desempenho agronômico do feijão-vagem, cv. Alessa, cultivado sobre cobertura viva perene de grama-batatais (Paspalum notatum Flüggé e de amendoim forrageiro (Arachis pintoi Krapov & Gregory, e em solo convencionalmente preparado, como controle. Diferentes doses de cama de aviário (0, 7, 14 e 28 t ha-1 foram fornecidas, parceladamente, em um Planossolo, em Seropédica, RJ, de agosto a outubro de 2002. O delineamento adotado foi o de blocos ao acaso, dispostos em parcelas subdivididas, com quatro repetições, utilizando-se modelo quadrático para análise dos resultados. A produtividade de vagens foi semelhante nos três sistemas de cultivo sem efeito competitivo das espécies de cobertura viva, sobre as quais foi realizada a semeadura direta da cultura, com enxada. A produtividade máxima estimada pelo modelo de regressão foi 20,3 t ha-1 de vagens. Esse valor foi obtido com a dose de 26 t ha-1 de cama de aviário, aplicada de forma parcelada. A semeadura direta de feijão-vagem sobre cobertura viva perene de grama-batatais e de amendoim forrageiro é viável, com resultados preliminares positivos.The objective of this work was to evaluate the agronomic performance of snap bean planted on living perennial mulch of bahia grass (Paspalum notatum Flüggé and of peanut (Arachis pintoi Krapov & Gregory and in a conventional tillage soil as a control. Different parcels and doses of poultry bed manure (0, 7, 14 and 28 t ha-1 were used in a Planosol soil from August to October of 2002. The statistical design was a split plot, in completely randomized blocks, with four replications, using a quadratic model to analyze the results. Snap bean yield was similar for the tillage system treatments without competition effect from the living mulch, in which direct seeding of the main crop was performed with a hoe. The greatest snap bean yield estimated by regression model was 20.3 t ha-1, corresponding to the dose of

  10. Soil nitrogen mineralization not affected by grass species traits

    Science.gov (United States)

    Maged Ikram Nosshi; Jack Butler; M. J. Trlica

    2007-01-01

    Species N use traits was evaluated as a mechanism whereby Bromus inermis (Bromus), an established invasive, might alter soil N supply in a Northern mixed-grass prairie. We compared soils under stands of Bromus with those from three representative native grasses of different litter C/N: Andropogon...

  11. Persistence of Overseeded Cool-Season Grasses in Bermudagrass Turf

    OpenAIRE

    Thomas Serensits; Matthew Cutulle; Jeffrey F. Derr

    2011-01-01

    Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual) ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass di...

  12. Anaerobic co-digestion of perennials: Methane potential and digestate nitrogen fertilizer value

    DEFF Research Database (Denmark)

    Muller-Stover, Dorette Sophie; Sun, Guotao; Kroff, Pablo

    2016-01-01

    Co-digestion of crop biomass improves the traditional manure-based biogas yield due to an increased content of easily degradable carbon compounds. In this study, the methane potential of three perennials (grass, legumes, and grass+legume) was determined using various amounts together with animal ...

  13. Evaluating winter/spring seeding of a native perennial bunchgrass in the sagebrush steppe

    Science.gov (United States)

    Sagebrush (Artemisia tridentata Nutt.) plant communities in the US Great Basin region are being severely impacted by increasingly frequent wildfires in association with the expansion of exotic annual grasses. Maintenance of native perennial bunchgrasses is key to controlling annual grass expansion,...

  14. Perennial ryegrass for dairy cows: Intake, milk production and nitrogen utilization

    NARCIS (Netherlands)

    Tas, B.M.

    2005-01-01

    Keywords: perennial ryegrass, dairy cows, intake, digestibility milk production, nitrogen utilisation.In the Netherlands, grass is one of the main roughages in the diet of high productive dairy cows. Grass is associated with two main problems: the limited dry matter intake (DMI)

  15. Genetic markers for flowering in perennial ryegrass

    DEFF Research Database (Denmark)

    Paina, Cristiana; Byrne, Stephen; Andersen, Jeppe Reitan

    2011-01-01

    Perennial ryegrass (Lolium perenne L.) is the principal forage grass utilized in Danish agriculture and underpins the beef and dairy sectors. It is characterized as having high digestibility, high nutritional value, and high productivity during vegetative growth. However, at the reproductive growth...... genes will be converted to molecular markers and mapped in an existing mapping population previously characterized for flowering time and vernalization response. References: Amasino, R.M., Michaels S.D. (2010). The Timing of Flowering. Plant Physiology 154: 516–520 Greenup, A., W. Peacock, W.J., Dennis...

  16. Transcriptional Profiling and Identification of Heat-Responsive Genes in Perennial Ryegrass by RNA-Sequencing

    Directory of Open Access Journals (Sweden)

    Kehua Wang

    2017-06-01

    Full Text Available Perennial ryegrass (Lolium perenne is one of the most widely used forage and turf grasses in the world due to its desirable agronomic qualities. However, as a cool-season perennial grass species, high temperature is a major factor limiting its performance in warmer and transition regions. In this study, a de novo transcriptome was generated using a cDNA library constructed from perennial ryegrass leaves subjected to short-term heat stress treatment. Then the expression profiling and identification of perennial ryegrass heat response genes by digital gene expression analyses was performed. The goal of this work was to produce expression profiles of high temperature stress responsive genes in perennial ryegrass leaves and further identify the potentially important candidate genes with altered levels of transcript, such as those genes involved in transcriptional regulation, antioxidant responses, plant hormones and signal transduction, and cellular metabolism. The de novo assembly of perennial ryegrass transcriptome in this study obtained more total and annotated unigenes compared to previously published ones. Many DEGs identified were genes that are known to respond to heat stress in plants, including HSFs, HSPs, and antioxidant related genes. In the meanwhile, we also identified four gene candidates mainly involved in C4 carbon fixation, and one TOR gene. Their exact roles in plant heat stress response need to dissect further. This study would be important by providing the gene resources for improving heat stress tolerance in both perennial ryegrass and other cool-season perennial grass plants.

  17. Cluster fescue (Festuca paradoxa Desv.): A multipurpose native cool-season grass

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; J.W. Van Sambeek; R.A. Pierce

    2005-01-01

    Native cool-season grasses (NCSG) are adapted to a wide range of habitats and environmental conditions, and cluster fescue (Festuca paradoxa Desv.) is no exception. Cluster fescue can be found in unplowed upland prairies, prairie draws, savannas, forest openings, and glades (Aiken et al. 1996). Although its range includes 23 states in the continental...

  18. Phenotypic and genetic characterization of western prairie clover collections from the western USA

    Science.gov (United States)

    Kishor Bhattarai; B. Shaun Bushman; Douglas A. Johnson; John G. Carman

    2010-01-01

    Few North American legumes are available for rangeland revegetation in the semiarid western United States. Western prairie clover (Dalea ornata [Douglas ex Hook.] Eaton & J. Wright) is a perennial legume with desirable forage characteristics and is distributed in the northern Great Basin, Snake River Basin, and southern Columbia Plateau. Understanding the...

  19. Rangewide genetic analysis of Lesser Prairie-Chicken reveals population structure, range expansion, and possible introgression

    Science.gov (United States)

    Oyler-McCance, Sara J.; DeYoung, Randall W; Fike, Jennifer; Hagen, Christian A.; Johnson, Jeff A.; Larsson, Lena C.; Patten, Michael

    2016-01-01

    The distribution of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) has been markedly reduced due to loss and fragmentation of habitat. Portions of the historical range, however, have been recolonized and even expanded due to planting of conservation reserve program (CRP) fields that provide favorable vegetation structure for Lesser Prairie-Chickens. The source population(s) feeding the range expansion is unknown, yet has resulted in overlap between Lesser and Greater Prairie-Chickens (T. cupido) increasing the potential for hybridization. Our objectives were to characterize connectivity and genetic diversity among populations, identify source population(s) of recent range expansion, and examine hybridization with the Greater Prairie-Chicken. We analyzed 640 samples from across the range using 13 microsatellites. We identified three to four populations corresponding largely to ecoregions. The Shinnery Oak Prairie and Sand Sagebrush Prairie represented genetically distinct populations (F ST > 0.034 and F ST > 0.023 respectively). The Shortgrass/CRP Mosaic and Mixed Grass ecoregions appeared admixed (F ST = 0.009). Genetic diversity was similar among ecoregions and N e ranged from 142 (95 % CI 99–236) for the Shortgrass/CRP Mosaic to 296 (95 % CI 233–396) in the Mixed Grass Prairie. No recent migration was detected among ecoregions, except asymmetric dispersal from both the Mixed Grass Prairie and to a lesser extent the Sand Sagebrush Prairie north into adjacent Shortgrass/CRP Mosaic (m = 0.207, 95 % CI 0.116–0.298, m = 0.097, 95 % CI 0.010–0.183, respectively). Indices investigating potential hybridization in the Shortgrass/CRP Mosaic revealed that six of the 13 individuals with hybrid phenotypes were significantly admixed suggesting hybridization. Continued monitoring of diversity within and among ecoregions is warranted as are actions promoting genetic connectivity and range expansion.

  20. Citizen knowledge and perception of black-tailed prairie dog management: Report to respondents

    Science.gov (United States)

    Sexton, Natalie R.; Brinson, Ayeisha; Ponds, Phadrea D.; Cline, Kurt; Lamb, Berton L.

    2001-01-01

    What do citizens know about black-tailed prairie dogs, and where do they get their information? When management decisions need to be made regarding an animal such as the black-tailed prairie dog, an understanding of the species and its relationship to humans is necessary. This includes knowing the biology of the animal, where it lives, and how it interacts with other animals. But it is equally important for those making decisions about the species to understand citizens’ knowledge and perceptions so managers can effectively communicate with the public and help the public participate in planning and decision making activities. Unfortunately, what is known about public knowledge, perception, and preferences concerning prairie dog management is limited to data from only a few areas. This study attempts to answer the question: What do people in the short-grass prairie region of the United States know and think about black-tailed prairie dogs?

  1. A comparison of native tallgrass prairie and plains bluestem forage systems for cow-calf production in the southern great plains.

    Science.gov (United States)

    Coleman, S W; Phillips, W A; Volesky, J D; Buchanan, D

    2001-07-01

    The objective of this study was to compare an introduced warm-season perennial grass (plains bluestem, Bothriochloa ischaemum) to native tallgrass prairie for cow-calf production. Three systems were used, two based on tallgrass prairie with two different forms of protein supplementation and one based on plains bluestem as the primary forage. The systems were as follows: 1) native tallgrass prairie with pelleted oilseed meal as the winter protein supplement (native-control); 2) native tallgrass prairie with limited access to wheat pasture as the winter protein supplement (native-wheat); and 3) plains bluestem with limited access to wheat pasture as the protein supplement (bluestem-wheat). Oilseed meal protein supplements were fed twice weekly. Cows grazing wheat pasture were allowed 6 h of grazing twice weekly. Ninety-nine cows per year were used over the 3-yr study. Cows were sired by either Charolais, Gelbvieh, Angus, or Hereford bulls out of commercial Angus-Hereford dams. Calves were sired by Simmental bulls. Calving and weaning rate increased over time but did not differ among systems or breed types. System did not influence the size or body condition score of cows or the performance of calves, but changes in the weight and condition scores of cows were greater on either native system than on the bluestem-wheat system. Cows from Charolais and Gelbvieh bulls were taller (P < 0.05), and heavier (P < 0.05), and weaned heavier (P < 0.05) calves than cows from Angus or Hereford bulls. The weight of cows on the bluestem-wheat system tended to decrease over time, whereas cows grazing on the native systems tended to gain weight over time. The native-control system was the most profitable system based on cow production. If excess hay produced from the bluestem-wheat system was sold as a cash crop, then this system was the most profitable. In general, we conclude that limit-grazing wheat pasture is a viable alternative to oilseed meal as protein supplement for wintering

  2. Prairie Conservation in Canada: The Prairie Conservation Action Plan Experience

    Science.gov (United States)

    Dean Nernberg; David Ingstrup

    2005-01-01

    In Canada, grassland conservation has been mobilized and directed through the development of Prairie Conservation Action Plans and Action Plan Committees in the three prairie provinces of Alberta (45 partner agencies and organizations), Saskatchewan (26 partners), and Manitoba (26 partners). In Alberta, 43 percent of the native prairie remains; in Saskatchewan and...

  3. Estabelecimento de gramíneas forrageiras tropicais perenes simultaneamente com as culturas de milho e soja no Norte do RS Perennial tropical forage grasses establishment simultaneously with soybean and maize in northern of RS state, Brazil

    Directory of Open Access Journals (Sweden)

    Franciele Mariani

    2012-08-01

    ça' single pasture was higher than the others, with average accumulation of 6.515 and 5.778kg ha-1, respectively. Intercropped with maize the average accumulation of dry matter was 2.380kg ha-1, without significant differences between species, but with the greatest accumulation occurred in soybeans for 'Marandu' (3.040kg ha-1. There was no decrease in soybean and maize yield in presence of forages, but for mechanical harvesting of soybean further investigation will be required. The intercropping between maize and tropical perennial forages is a viable alternative to the northern of RS.

  4. Interspecific nutrient transfer in a tallgrass prairie plant community

    International Nuclear Information System (INIS)

    Walter, L.E.F.; Hartnett, D.C.; Hetrick, B.A.D.; Schwab, A.P.

    1996-01-01

    Interplant nutrient transfer may be an important ecological process in grasslands, and may significantly influence plant neighborhood interactions. We investigated the potential for phosphorus transfer between the dominant grass Andropogon gerardii and several neighboring plant species in tallgrass prairie via a field 32PO4 labelling experiment. The mean amount of 32P received from donor shoots differed significantly among neighboring species and decreased with increasing distance from the donor. In general, forbs and cool-season C3 grasses received more labelled 32P than warm-season C4 grasses. Phosphorus transfer occurred over distances up to 0.5 m. The effects of species and distance on movement of phosphorus changed with increasing time after labelling. The relative mass of receiver and donor shoots did not affect amounts of 32P transfer. A benomyl fungicide treatment, applied to suppress mycorrhizal activity, likely did not affect existing vegetative hyphae and did not affect the amount of 32P transferred. These studies demonstrate that: (1) phosphorus is transferred among neighboring species in tallgrass prairie plant communities, (2) phosphorus may be transferred over significantly greater distances than reported in other grasslands, and (3) there is differential transfer among co-occurring species. Hypothesized mechanisms accounting for these patterns in tallgrass prairie include mycorrhizal hyphal interconnections and/or extensive and differential root and rhizosphere overlap among neighboring species

  5. The genome and transcriptome of perennial ryegrass mitochondria

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul; Studer, Bruno; Byrne, Stephen

    2013-01-01

    Background: Perennial ryegrass (Lolium perenne L.) is one of the most important forage and turf grass species of temperate regions worldwide. Its mitochondrial genome is inherited maternally and contains genes that can influence traits of agricultural importance. Moreover, the DNA sequence...... and annotation of the complete mitochondrial genome from perennial ryegrass. Results: Intact mitochondria from perennial ryegrass leaves were isolated and used for mtDNA extraction. The mitochondrial genome was sequenced to a 167-fold coverage using the Roche 454 GS-FLX Titanium platform, and assembled...... of mitochondrial genomes has been established and compared for a large number of species in order to characterize evolutionary relationships.Therefore, it is crucial to understand the organization of the mitochondrial genome and how it varies between and within species. Here, we report the first de novo assembly...

  6. Interactive effects between nest microclimate and nest vegetation structure confirm microclimate thresholds for Lesser Prairie-Chicken nest survival

    Science.gov (United States)

    Grisham, Blake A.; Godar, Alixandra J.; Boal, Clint W.; Haukos, David A.

    2016-01-01

    The range of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) spans 4 unique ecoregions along 2 distinct environmental gradients. The Sand Shinnery Oak Prairie ecoregion of the Southern High Plains of New Mexico and Texas is environmentally isolated, warmer, and more arid than the Short-Grass, Sand Sagebrush, and Mixed-Grass Prairie ecoregions in Colorado, Kansas, Oklahoma, and the northeast panhandle of Texas. Weather is known to influence Lesser Prairie-Chicken nest survival in the Sand Shinnery Oak Prairie ecoregion; regional variation may also influence nest microclimate and, ultimately, survival during incubation. To address this question, we placed data loggers adjacent to nests during incubation to quantify temperature and humidity distribution functions in 3 ecoregions. We developed a suite of a priori nest survival models that incorporated derived microclimate parameters and visual obstruction as covariates in Program MARK. We monitored 49 nests in Mixed-Grass, 22 nests in Sand Shinnery Oak, and 30 nests in Short-Grass ecoregions from 2010 to 2014. Our findings indicated that (1) the Sand Shinnery Oak Prairie ecoregion was hotter and drier during incubation than the Mixed- and Short-Grass ecoregions; (2) nest microclimate varied among years within ecoregions; (3) visual obstruction was positively associated with nest survival; but (4) daily nest survival probability decreased by 10% every half-hour when temperature was greater than 34°C and vapor pressure deficit was less than −23 mmHg during the day (about 0600–2100 hours). Our major finding confirmed microclimate thresholds for nest survival under natural conditions across the species' distribution, although Lesser Prairie-Chickens are more likely to experience microclimate conditions that result in nest failures in the Sand Shinnery Oak Prairie ecoregion. The species would benefit from identification of thermal landscapes and management actions that promote cooler, more humid nest microclimates.

  7. Soil water status under perennial and annual pastures on an acid duplex soil

    International Nuclear Information System (INIS)

    Heng, L.K.; White, R.E.; Chen, D.

    2000-01-01

    A comprehensive field study of soil water balance, nitrogen (N) cycling, pasture management and animal production was carried out on an acid duplex soil at Book Book near Wagga Wagga in southern New South Wales. The experiment, carried out over a 3-year period, tested the hypothesis that sown perennial grass pastures improve the sustainability of a grazing system through better use of water and N. The treatments were: annual pastures without lime (AP-), annual pastures with lime (AP+), perennial pastures without lime (PP-) and perennial pastures with lime (PP+). Soil water measurement was made using a neutron probe on one set of the treatments comprising four adjacent paddocks. Over three winter and spring periods, the results showed that perennial grass pastures, especially PP+, consistently extracted about 40 mm more soil water each year than did the annual grass pastures. As a result, surface runoff, sub-surface flow and deep drainage (percolation below 180 cm depth) were about 40 mm less from the perennial pastures. The soil water status of the four pasture treatments was simulated reasonably well using a simple soil water model. Together with the long-term simulation of deep drainage, using past meteorological records, it is shown that proper management of perennial pastures can reduce recharge to groundwater and make pastoral systems more sustainable in the high rainfall zone. However, to completely reduce recharge, more-deeply rooted plants or trees are needed. (author)

  8. Seasonal versus perennial immunotherapy: evaluation after three years of treatment.

    Science.gov (United States)

    Muñoz Lejarazu, D; Bernaola, G; Fernández, E; Audícana, M; Ventas, P; Martín, S; Fernández de Corres, L

    1993-01-01

    We have performed a comparative study to evaluate seasonal and perennial schedules after 3 years of immunotherapy. Sixty patients suffering from rhinitis and/or asthma due to grass pollen sensitization were randomly allocated to receive a semi-depot extract of Phleum pratense according to a perennial or seasonal schedule. The last year of the study, 14 patients were recruited as a control group without immunotherapy. The cumulative dose was 602 BU in the perennial group and 372 BU in the seasonal group. The frequency and severity of side-effects were similar and very low in both treated groups. The IgE level was significantly lower after perennial immunotherapy at the end of the first 2 years. A seasonal decrease in specific IgG levels was observed in patients who interrupted immunotherapy, while this was not observed in patients under the perennial schedule. Symptoms and medication scores did not show differences between groups. Nevertheless, we found a significant difference between treated patients and the control group.

  9. Perennial Environment Observatory

    International Nuclear Information System (INIS)

    Plas, Frederic

    2014-07-01

    The Perennial Environment Observatory [Observatoire Perenne de l'Environnement - OPE] is a unique approach and infrastructure developed and implemented by ANDRA, the French National Radioactive Waste Management Agency, as part of its overall project of deep geological disposal for radioactive waste. Its current mission is to assess the initial state of the rural (forest, pasture, open-field and aquatic) environment, prior to repository construction. This will be followed in 2017 (pending construction authorizations) and for a period exceeding a century, by monitoring of any impact the repository may have on the environment. In addition to serving its own industrial purpose of environmental monitoring, ANDRA also opens the OPE approach, infrastructure and acquired knowledge (database...) to the scientific community to support further research on long term evolution of the environment subjected to natural and anthropogenic stresses, and to contribute to a better understanding of the interaction between the various compartments of the environment

  10. Direct and indirect effects of climate change on a prairie plant community.

    Directory of Open Access Journals (Sweden)

    Peter B Adler

    2009-09-01

    Full Text Available Climate change directly affects species by altering their physical environment and indirectly affects species by altering interspecific interactions such as predation and competition. Recent studies have shown that the indirect effects of climate change may amplify or counteract the direct effects. However, little is known about the the relative strength of direct and indirect effects or their potential to impact population persistence.We studied the effects of altered precipitation and interspecific interactions on the low-density tiller growth rates and biomass production of three perennial grass species in a Kansas, USA mixed prairie. We transplanted plugs of each species into local neighborhoods of heterospecific competitors and then exposed the plugs to a factorial manipulation of growing season precipitation and neighbor removal. Precipitation treatments had significant direct effects on two of the three species. Interspecific competition also had strong effects, reducing low-density tiller growth rates and aboveground biomass production for all three species. In fact, in the presence of competitors, (log tiller growth rates were close to or below zero for all three species. However, we found no convincing evidence that per capita competitive effects changed with precipitation, as shown by a lack of significant precipitation x competition interactions.We found little evidence that altered precipitation will influence per capita competitive effects. However, based on species' very low growth rates in the presence of competitors in some precipitation treatments, interspecific interactions appear strong enough to affect the balance between population persistence and local extinction. Therefore, ecological forecasting models should include the effect of interspecific interactions on population growth, even if such interaction coefficients are treated as constants.

  11. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

    Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula

    2012-01-01

    , we address crucial topics to implement hybrid breeding, such as the availability and development of heterotic groups, as well as biological mechanisms for hybridization control such as self-incompatibility (SI) and male sterility (MS). Finally, we present potential hybrid breeding schemes based on SI...... of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods...

  12. Soil nutrient heterogeneity alters competition between two perennial grass species

    NARCIS (Netherlands)

    Fransen, B.; Kroon, de H.; Berendse, F.

    2001-01-01

    Differences in root foraging behavior between species have been well documented, but the effects of these differences on belowground competitive ability are only beginning to be studied. Here we report the results of a competition experiment in homogeneous and heterogeneous soils between two species

  13. Development of Perennial Grain Sorghum

    Directory of Open Access Journals (Sweden)

    Stan Cox

    2018-01-01

    Full Text Available Perennial germplasm derived from crosses between Sorghum bicolor and either S. halepense or S. propinquum is being developed with the goal of preventing and reversing soil degradation in the world’s grain sorghum-growing regions. Perennial grain sorghum plants produce subterranean stems known as rhizomes that sprout to form the next season’s crop. In Kansas, breeding perennial sorghum involves crossing S. bicolor cultivars or breeding lines to S. halepense or perennial S. bicolorn × S. halepense breeding lines, selecting perennial plants from F2 or subsequent populations, crossing those plants with S. bicolor, and repeating the cycle. A retrospective field trial in Kansas showed that selection and backcrossing during 2002–2009 had improved grain yields and seed weights of breeding lines. Second-season grain yields of sorghum lines regrowing from rhizomes were similar to yields in the first season. Further selection cycles have been completed since 2009. Many rhizomatous lines that cannot survive winters in Kansas are perennial at subtropical or tropical locations in North America and Africa. Grain yield in Kansas was not correlated with rhizomatousness in either Kansas or Uganda. Genomic regions affecting rhizome growth and development have been mapped, providing new breeding tools. The S. halepense gene pool may harbor many alleles useful for improving sorghum for a broad range of traits in addition to perenniality.

  14. Testing water-soluble carbohydrate QTL effects in perennial ryegrass (Lolium perenne L.) by marker selection

    NARCIS (Netherlands)

    Turner, L.B.; Farrell, M.; Humphreys, M.O.; Dolstra, O.

    2010-01-01

    Water-soluble carbohydrates (WSC) are an important factor determining the nutritional value of grass forage and development of genetic markers for selection of WSC traits in perennial ryegrass would benefit future breeding programmes. Quantitative trait loci (QTLs) for WSC have been published for an

  15. Cultivar effects of perennial ryegrass on herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.

    2006-01-01

    Perennial ryegrass is the most abundant grass species in temperate climates. An increased herbage intake of dairy cows by breeding new cultivars could have a large potential impact on agriculture. The effects of cultivars on sward structure, nutritive value, physical characteristics and disease

  16. Association of candidate genes with drought tolerance traits in diverse perennial ryegrass accessions

    Science.gov (United States)

    Xiaoqing Yu; Guihua Bai; Shuwei Liu; Na Luo; Ying Wang; Douglas S. Richmond; Paula M. Pijut; Scott A. Jackson; Jianming Yu; Yiwei. Jiang

    2013-01-01

    Drought is a major environmental stress limiting growth of perennial grasses in temperate regions. Plant drought tolerance is a complex trait that is controlled by multiple genes. Candidate gene association mapping provides a powerful tool for dissection of complex traits. Candidate gene association mapping of drought tolerance traits was conducted in 192 diverse...

  17. Nitrous oxide emission and soil carbon sequestration from herbaceous perennial biofuel feedstocks

    Science.gov (United States)

    Greenhouse gas (GHG) mitigation and renewable, domestic fuels are needed in the United States. Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks that may meet this need. However, managing perennial grasses for feedstock requires nitro...

  18. Postharvest residues from grass seed crops for bioenergy

    OpenAIRE

    Simić, Aleksandar; Čolić, Vladislava; Vučković, Savo; Dželetović, Željko; Bijelić, Zorica; Mandić, Violeta

    2016-01-01

    During grass seed production, a large amount of low forage quality biomass has been produced. Tall growing perennial grasses such as tall fescue (Festuca arundinacea L.) and Italian ryegrass (Lolium multiflorum Lam.) can be used as an alternative source for bioenergy production as they can be grown in less cultivated areas, their residues in seed production could be valuable energy source and can be potentially used as a dual purpose crop (bioenergy and forage). In this research, potentials o...

  19. Interference between perennial grassland and Lavandula stoechas subsp. pedunculata seedlings: a case of spatial segregation cause by competition

    Science.gov (United States)

    Sánchez, Ana M.; Peco, Begoña

    2004-07-01

    This paper analyses the relationship between Lavandula stoechas subsp. pedunculata, a common Mediterranean scrub species in central Iberia, and perennial grasslands. While Lavandula gives rise to almost monospecific formations in intermediate and upper hill zones, perennial grasses occupy the low areas. The proposed explanatory hypothesis for this spatial distribution is that the scrub is unable to establish itself in grasslands with heavy spatial occupation. We designed two experiments to test this hypothesis, one which analysed the effect of perennial grass cover on Lavandula establishment, and another which focused on its influence on previously implanted seedling survival and growth, distinguishing the effect of shoot and root interference. The results show negative interference during establishment and later in the use of light and nutrients. This results in a very low overall survival probability, with only 1.4% of seedlings surviving the first growth period. This low success rate explains the existence of a clear spatial segregation between scrub patches and perennial-dominated grasslands.

  20. Evaluating grasses as a long-term energy resource

    Energy Technology Data Exchange (ETDEWEB)

    Christian, D.G.; Riche, A.B.

    2001-07-01

    The work reported here is part of an ongoing project that aims to evaluate the yields of three perennial rhizomatous grasses and determine their suitability as bio-energy crops. The work began in 1993, and the grasses have been monitored continuously since that time. This report covers the period 1999/2000, and includes: the performance of plots of the energy grasses Miscanthus grass, switchgrass and reed canary grass seven years after they were planted; assessment of the yield of 15 genotypes of Miscanthus planted in 1997; monitoring all the species throughout the growing period for the presence of pests, weeds and diseases; measurement of the amount of nitrate leached from below Miscanthus grass; investigating the occurrence of lodging in switchgrass. (Author)

  1. Comparison of the fatty acid composition of fresh and ensiled perennial ryegrass (Lolium perenne L.), affected by cultivar and regrowth interval

    NARCIS (Netherlands)

    Elgersma, A.; Ellen, G.; Horst, van der H.; Muuse, B.G.; Boer, H.; Tamminga, S.

    2003-01-01

    Two experiments were conducted to evaluate the effects of grass cultivar and regrowth stage on the fatty acid (FA) profile in fresh and ensiled perennial ryegrass (Lolium perenne L.). The Experiment 1 compared the composition of fresh grass with that of pre-wilted ensiled material of six cultivars,

  2. Breeding biologies, pollinators and seed beetles of two prairie-clovers, Dalea ornata and D. searlsiae (Fabaceae: Amorpheae), from the Intermountain West USA

    Science.gov (United States)

    Two prairie-clovers, Dalea ornata and D. searlsiae, are perennial forbs that flower during early summer throughout the Colombia Plateau and Great Basin of the western USA, respectively. Their seed is desirable for use in rangeland restoration. We experimentally characterized the breeding biologies ...

  3. Grass genomes

    OpenAIRE

    Bennetzen, Jeffrey L.; SanMiguel, Phillip; Chen, Mingsheng; Tikhonov, Alexander; Francki, Michael; Avramova, Zoya

    1998-01-01

    For the most part, studies of grass genome structure have been limited to the generation of whole-genome genetic maps or the fine structure and sequence analysis of single genes or gene clusters. We have investigated large contiguous segments of the genomes of maize, sorghum, and rice, primarily focusing on intergenic spaces. Our data indicate that much (>50%) of the maize genome is composed of interspersed repetitive DNAs, primarily nested retrotransposons that in...

  4. Detecting bacterial endophytes in tropical grasses of the Brachiaria ...

    African Journals Online (AJOL)

    Plant-growth-promoting (PGP) bacteria include a diverse group of soil bacteria thought to stimulate plant growth by various mechanisms. Brachiaria forage grasses, of African origin, are perennials that often grow under low-input conditions and are likely to harbour unique populations of PGP bacteria. Three bacterial strains ...

  5. An emerging crisis across northern prairie refuges: Prevalence of invasive plants and a plan for adaptive management

    Science.gov (United States)

    Grant, T.A.; Flanders-Wanner, B.; Shaffer, T.L.; Murphy, R.K.; Knutsen, G.A.

    2009-01-01

    In the northern Great Plains, native prairies managed by the U.S. Fish and Wildlife Service (Service) can be pivotal in conservation of North America's biological diversity. From 2002 to 2006, we surveyed 7,338 belt transects to assess the general composition of mixed-grass and tallgrass prairie vegetation across five "complexes" (i.e., administrative groupings) of national wildlife refuges managed by the Service in North Dakota and South Dakota. Native grasses and forbs were common (mean frequency of occurrence 47%-54%) on two complexes but uncommon (4%-13%) on two others. Conversely, an introduced species of grass, smooth brome (Bromus inermis), accounted for 45% to 49% of vegetation on two complexes and another species, Kentucky bluegrass (Poa pratensis) accounted for 27% to 36% of the vegetation on three of the complexes. Our data confirm prior suspicions of widespread invasion by introduced species of plants on Service-owned tracts of native prairie, changes that likely stem in part from a common management history of little or no disturbance (e.g., defoliation by grazing or fire). However, variability in the degree and type of invasion among prairie tracts suggests that knowledge of underlying causes (e.g., edaphic or climatic factors, management histories) could help managers more effectively restore prairies. We describe an adaptive management approach to acquire such knowledge while progressing with restoration. More specifically, we propose to use data from inventories of plant communities on Service-owned prairies to design and implement, as experiments, optimal restoration strategies. We will then monitor these experiments and use the results to refine future strategies. This comprehensive, process-oriented approach should yield reliable and robust recommendations for restoration and maintenance of native prairies in the northern Great Plains. 2009 by the Board of Regents of the University of Wisconsin System.

  6. Persistence of Overseeded Cool-Season Grasses in Bermudagrass Turf

    Directory of Open Access Journals (Sweden)

    Thomas Serensits

    2011-01-01

    Full Text Available Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally persisted the most one year after seeding, either because of summer survival of plants or because of new germination the following fall. Plant counts one year after seeding were greater in the higher seeding rate treatment compared to the lower seeding treatment rate of perennial ryegrass, suggesting new germination had occurred. Plant counts one year after seeding plots with intermediate ryegrass or Italian ryegrass were attributed primarily to latent germination and not summer survival. Applications of foramsulfuron generally did not prevent overseeded species stand one year after seeding, supporting the conclusion of new germination. Although quality is less with intermediate ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year later.

  7. Controlling grass weeds on hard surfaces

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2012-01-01

    An experiment was conducted on a specially designed hard surface to study the impact of time interval between flaming treatments on the regrowth and flower production of two grass weeds. The goal of this experiment was to optimize the control of annual bluegrass and perennial ryegrass, both species...... that are very difficult to control without herbicides. Aboveground biomass from 72 plants per treatment was harvested and dry weights were recorded at regular intervals to investigate how the plants responded to flaming. Regrowth of the grasses was measured by harvesting aboveground biomass 2 wk after......, as they did not increase the reduction of aboveground biomass compared with the 7-d treatment interval. Knowledge on the regrowth of grass weeds after flaming treatments provided by this study can help improve recommendations given to road keepers and park managers for management on these weeds. Nomenclature...

  8. Native herbaceous perennials as ornamentals

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Ørgaard, Marian

    2013-01-01

    Gardening with native perennials is a way to bring nature closer to urban citizens and bring up reflections on nature in a busy world. During three seasons of trialing Salvia pratensis, Dianthus deltoides, Campanula trachelium, Vincetoxicum hirundinaria, Saxifraga granulata, Plantago media and P...

  9. A generic model for estimating biomass accumulation and greenhouse gas emissions from perennial crops

    Science.gov (United States)

    Ledo, Alicia; Heathcote, Richard; Hastings, Astley; Smith, Pete; Hillier, Jonathan

    2017-04-01

    Agriculture is essential to maintain humankind but is, at the same time, a substantial emitter of greenhouse gas (GHG) emissions. With a rising global population, the need for agriculture to provide secure food and energy supply is one of the main human challenges. At the same time, it is the only sector which has significant potential for negative emissions through the sequestration of carbon and offsetting via supply of feedstock for energy production. Perennial crops accumulate carbon during their lifetime and enhance organic soil carbon increase via root senescence and decomposition. However, inconsistency in accounting for this stored biomass undermines efforts to assess the benefits of such cropping systems when applied at scale. A consequence of this exclusion is that efforts to manage this important carbon stock are neglected. Detailed information on carbon balance is crucial to identify the main processes responsible for greenhouse gas emissions in order to develop strategic mitigation programs. Perennial crops systems represent 30% in area of total global crop systems, a considerable amount to be ignored. Furthermore, they have a major standing both in the bioenergy and global food industries. In this study, we first present a generic model to calculate the carbon balance and GHGs emissions from perennial crops, covering both food and bioenergy crops. The model is composed of two simple process-based sub-models, to cover perennial grasses and other perennial woody plants. The first is a generic individual based sub-model (IBM) covering crops in which the yield is the fruit and the plant biomass is an unharvested residue. Trees, shrubs and climbers fall into this category. The second model is a generic area based sub-model (ABM) covering perennial grasses, in which the harvested part includes some of the plant parts in which the carbon storage is accounted. Most second generation perennial bioenergy crops fall into this category. Both generic sub

  10. Land-use change, economics, and rural well-being in the Prairie Pothole Region of the United States

    Science.gov (United States)

    Gascoigne, William R.; Hoag, Dana L.K.; Johnson, Rex R.; Koontz, Lynne M.; Thomas, Catherine Cullinane

    2013-01-01

    This fact sheet highlights findings included in a comprehensive new report (see USGS Professional Paper 1800) which investigated land-use change, economic characteristics, and rural community well-being in the Prairie Pothole Region of the United States. Once one of the largest grassland-wetlands ecosystems on earth, the North American prairie has experienced extensive conversion to cultivated agriculture, with farming becoming the dominant land use in the region over the last century. Both perennial habitat lands and agricultural croplands retain importance economically, socially, and culturally. Greatly increased oil and gas development in recent years brought rises in employment and income but also stressed infrastructure, cost of living, and crime rates. Research described in these reports focuses on land-use dynamics and illuminates how economic variables and rural development in the Prairie Pothole Region might be influenced as land uses change.

  11. Exudate Chemical Profiles Derived from Lespedeza and Other Tallgrass Prairie Plant Species

    Science.gov (United States)

    2017-05-01

    Chemical Profiles Derived from Lespedeza and Other Tall- grass Prairie Plant Species. ERDC TN-17-1. Vicksburg, MS: U.S. Army Engineer Re- search and...200-1-52. Washington, DC: U.S. Army Corps of Engineers Headquarters, Civil Works. https://www.wbdg.org/ffc/army-coe/public-works-technical-bulletins...ERDC TN-17-1 May 2017 Approved for public release; distribution is unlimited. Exudate Chemical Profiles Derived from Lespedeza and Other

  12. Supporting Agricultural Ecosystem Services through the Integration of Perennial Polycultures into Crop Rotations

    Directory of Open Access Journals (Sweden)

    Peter Weißhuhn

    2017-12-01

    Full Text Available This review analyzes the potential role and long-term effects of field perennial polycultures (mixtures in agricultural systems, with the aim of reducing the trade-offs between provisioning and regulating ecosystem services. First, crop rotations are identified as a suitable tool for the assessment of the long-term effects of perennial polycultures on ecosystem services, which are not visible at the single-crop level. Second, the ability of perennial polycultures to support ecosystem services when used in crop rotations is quantified through eight agricultural ecosystem services. Legume–grass mixtures and wildflower mixtures are used as examples of perennial polycultures, and compared with silage maize as a typical crop for biomass production. Perennial polycultures enhance soil fertility, soil protection, climate regulation, pollination, pest and weed control, and landscape aesthetics compared with maize. They also score lower for biomass production compared with maize, which confirms the trade-off between provisioning and regulating ecosystem services. However, the additional positive factors provided by perennial polycultures, such as reduced costs for mineral fertilizer, pesticides, and soil tillage, and a significant preceding crop effect that increases the yields of subsequent crops, should be taken into account. However, a full assessment of agricultural ecosystem services requires a more holistic analysis that is beyond the capabilities of current frameworks.

  13. Belowground Water Dynamics Under Contrasting Annual and Perennial Plant Communities in an Agriculturally-Dominated Landscape

    Science.gov (United States)

    Mora, G.; Asbjornsen, H.; Helmers, M. J.; Shepherd, G. W.

    2005-12-01

    The conversion from grasslands and forests to row-crops in the Midwest has affected soil water cycling because plant characteristics are one of the main parameters determining soil storage capacity, infiltration rates, and surface runoff. Little is known, however, about the extent of modification of soil water dynamics under different plant communities. To address this important issue, we are documenting soil water dynamics under contrasting perennial and annual plant communities in an agriculturally-dominated landscape. Measurements of soil moisture and depths of uptake of source water were obtained for six vegetative cover types (corn and soybean field, brome pasture, degraded savanna, restored savanna, and restored prairie) at the Neal Smith National Wildlife Refuge in Prairie City, Iowa. The depths of uptake of soil water were determined on the basis of oxygen isotope composition of soil water and stem water. Measurements were performed once a month during an entire growing season. Preliminary results indicate that soil water present under the different vegetation types show similar profiles with depth during the dry months. Soil water in the upper 5 cm is enriched in oxygen-18 by about 5 per mil relative to soil water at 100 cm. Our preliminary results also indicate that the isotopic composition of stem water from annual plants is typically higher by about 2 per mil relative to that of stem water from perennial plants during the dry period. Whereas the oxygen isotopic composition for corn stem water is -5.49 per mil, that for elm and oak stem water is -7.62 and -7.51 per mil, respectively. The higher isotope values for corn suggest that annual crop plants are withdrawing water from shallower soil horizons relative to perennial plants. Moreover, our preliminary data suggest lower moisture content in soil under annual plant cover. We propose that the presence of deeper roots in the perennial vegetation allows these plants to tap into deeper water sources when

  14. Predator selection of prairie landscape features and its relation to duck nest success

    Science.gov (United States)

    Phillips, M.L.; Clark, W.R.; Sovada, M.A.; Horn, D.J.; Koford, Rolf R.; Greenwood, R.J.

    2003-01-01

    Mammalian predation is a major cause of mortality for breeding waterfowl in the U.S. Northern Great Plains, and yet we know little about the selection of prairie habitats by predators or how this influences nest success in grassland nesting cover. We selected 2 41.4-km2 study areas in both 1996 and 1997 in North Dakota, USA, with contrasting compositions of perennial grassland. A study area contained either 15-20% perennial grassland (Low Grassland Composition [LGC]) or 45-55% perennial grassland (High Grassland Composition [HGC]). We used radiotelemetry to investigate the selection of 9 landscape cover types by red fox (Vulpes vulpes) and striped skunk (Mephitis mephitis), while simultaneously recording duck nest success within planted cover. The cover types included the edge and core areas of planted cover, wetland edges within planted cover or surrounded by cropland, pastureland, hayland, cropland, roads, and miscellaneous cover types. Striped skunks selected wetland edges surrounded by agriculture over all other cover types in LGC landscapes (P-values for all pairwise comparisons were foraging efficiency in the interior areas of planted cover and contributed to higher nest success in HGC landscapes. Our observations of predator cover-type selection not only support the restoration and management of large blocks of grassland but also indicate the influence of alternative cover types for mitigating nest predation in the Prairie Pothole Region.

  15. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion

    Science.gov (United States)

    Xiaobo Zhou; Matthew J. Helmers; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer

    2010-01-01

    Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to...

  16. Managing for Multifunctionality in Perennial Grain Crops

    Science.gov (United States)

    Ryan, Matthew R; Crews, Timothy E; Culman, Steven W; DeHaan, Lee R; Hayes, Richard C; Jungers, Jacob M; Bakker, Matthew G

    2018-01-01

    Abstract Plant breeders are increasing yields and improving agronomic traits in several perennial grain crops, the first of which is now being incorporated into commercial food products. Integration strategies and management guidelines are needed to optimize production of these new crops, which differ substantially from both annual grain crops and perennial forages. To offset relatively low grain yields, perennial grain cropping systems should be multifunctional. Growing perennial grains for several years to regenerate soil health before rotating to annual crops and growing perennial grains on sloped land and ecologically sensitive areas to reduce soil erosion and nutrient losses are two strategies that can provide ecosystem services and support multifunctionality. Several perennial cereals can be used to produce both grain and forage, and these dual-purpose crops can be intercropped with legumes for additional benefits. Highly diverse perennial grain polycultures can further enhance ecosystem services, but increased management complexity might limit their adoption. PMID:29662249

  17. A synteny-based draft genome sequence of the forage grass Lolium perenne

    DEFF Research Database (Denmark)

    Byrne, Stephen; Nagy, Istvan; Pfeifer, Matthias

    2015-01-01

    -family of the grass family (Poaceae). Transcriptome data was used to identify 28 455 gene models, and we utilized macro-co-linearity between perennial ryegrass and barley, and synteny within the grass family, to establish a synteny-based linear gene order. The gametophytic self-incompatibility mechanism enables...

  18. The Performance of Early-Generation Perennial Winter Cereals at 21 Sites across Four Continents

    Directory of Open Access Journals (Sweden)

    Richard C. Hayes

    2018-04-01

    Full Text Available A network of 21 experiments was established across nine countries on four continents and spanning both hemispheres, to evaluate the relative performance of early generation perennial cereal material derived from wheat, rye, and barley and to inform future breeding strategies. The experimental lines were grown in replicated single rows, and first year production and phenology characteristics as well as yield and persistence for up to three years were monitored. The study showed that the existing experimental material is all relatively short-lived (≤3 years, with environments that are milder in summer and winter generally conferring greater longevity. No pedigree was superior across this diverse network of sites although better performing lines at the higher latitude sites were generally derived from Thinopyrum intermedium. By contrast, at lower latitudes the superior lines were generally derived from Th. ponticum and Th. elongatum parentage. The study observed a poor relationship between year 1 performance and productivity in later years, highlighting the need for perennial cereal material with greater longevity to underpin future experimental evaluation, and the importance for breeding programs to emphasize post-year 1 performance in their selections. Hybrid lines derived from the tetraploid durum wheat generally showed greater longevity than derivatives of hexaploid wheat, highlighting potential for greater use of Triticum turgidum in perennial wheat breeding. We advocate a model in future breeding initiatives that develops perennial cereal genotypes for specific target environments rather than a generic product for one global market. These products may include a diversity of cultivars derived from locally adapted annual and perennial parents. In this scenario the breeding program may have access to only a limited range of adapted perennial grass parents. In other situations, such as at very high latitude environments, perennial crops derived

  19. Genomics-Assisted Exploitation of Heterosis in Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul

    ryegrass for the development of improved varieties. During his PhD studies, Mohammad Shofiqul Islam studied the feasibility of developing novel hybrid breeding schemes based on cytoplasmic male sterility (CMS) systems in perennial ryegrass. He successfully completed the assembly and annotation of a male......-fertile perennial ryegrass mitochondrial genome, and identified candidate genes responsible for the CMS phenotype by comparing male-fertile and male-sterile mitochondrial genomes. His findings constitute a good basis for continuing research to produce hybrid grass varieties to address the future needs......, breeding activities have been carried out to improve the population and develop synthetic varieties. This does not fully exploit the potential of heterosis, however. Hybrid breeding is an alternative strategy and provides opportunities to fully exploit the genetically available heterosis in perennial...

  20. Genetic variation, population structure, and linkage disequilibrium in European elite germplasm of perennial ryegrass

    DEFF Research Database (Denmark)

    Brazauskas, Gintaras; Lenk, Ingo; Pedersen, Morten Greve

    2011-01-01

    Perennial ryegrass (Lolium perenne L.) is a highly valued temperate climate grass species grown as forage crop and for amenity uses. Due to its outbreeding nature and recent domestication, a high degree of genetic diversity is expected among cultivars. The aim of this study was to assess the extent...... of linkage disequilibrium (LD) within European elite germplasm and to evaluate the appropriate methodology for genetic association mapping in perennial ryegrass. A high level of genetic diversity was observed in a set of 380 perennial ryegrass elite genotypes when genotyped with 40 SSRs and 2 STS markers...... and occurred within 0.4 cM across European varieties, when population structure was taken into consideration. However, an extended LD of up to 6.6 cM was detected within the variety Aberdart. High genetic diversity and rapid LD decay provide means for high resolution association mapping in elite materials...

  1. Designing hybrid grass genomes to control runoff generation

    Science.gov (United States)

    MacLeod, C.; Binley, A.; Humphreys, M.; King, I. P.; O'Donovan, S.; Papadopoulos, A.; Turner, L. B.; Watts, C.; Whalley, W. R.; Haygarth, P.

    2010-12-01

    Sustainable management of water in landscapes requires balancing demands of agricultural production whilst moderating downstream effects like flooding. Pasture comprises 69% of global agricultural areas and is essential for producing food and fibre alongside environmental goods and services. Thus there is a need to breed forage grasses that deliver multiple benefits through increased levels of productivity whilst moderating fluxes of water. Here we show that a novel grass hybrid that combines the entire genomes of perennial ryegrass (Lolium perenne - the grass of choice for Europe’s forage agriculture) and meadow fescue (Festuca pratensis) has a significant role in flood prevention. Field plot experiments established differences in runoff generation with the hybrid cultivar reducing runoff by 50% compared to perennial ryegrass cultivar, and by 35% compared to a meadow fescue cultivar (34 events over two years, replicated randomized-block design, statistically significant differences). This important research outcome was the result of a project that combined plant genetics, soil physics and plot scale hydrology to identify novel grass genotypes that can reduce runoff from grassland systems. Through a coordinated series of experiments examining effects from the gene to plot scale, we have identified that the rapid growth and then turnover of roots in the L. perenne x F. pratensis hybrid is likely to be a key mechanism in reducing runoff generation. More broadly this is an exciting first step to realizing the potential to design grass genomes to achieve both food production, and to deliver flood control, a key ecosystem service.

  2. Long-term lesser prairie-chicken nest ecology in response to grassland management

    Science.gov (United States)

    Fritts, Sarah R.; Grisham, Blake A.; Haukos, David A.; Boal, Clint W.; Patten, Michael; Wolfe, Don H.; Dixon, Charles; Cox, Robert D.; Heck, Willard R.

    2016-01-01

    Long-term population and range declines from habitat loss and fragmentation caused the lesser prairie-chicken (Tympanuchus pallidicinctus) to be a species of concern throughout its range. Current lesser prairie-chicken range in New Mexico and Texas is partially restricted to sand shinnery oak (Quercus havardii; hereafter shinnery oak) prairies, on which cattle grazing is the main socioeconomic driver for private landowners. Cattle producers within shinnery oak prairies often focus land management on shrub eradication using the herbicide tebuthiuron to promote grass production for forage; however, herbicide application alone, and in combination with grazing, may affect nest site selection and nest survival of lesser prairie-chickens through the reduction of shinnery oak and native grasses. We used a controlled, paired, completely randomized design study to assess the influence of grazing and tebuthiuron application and their combined use on nest site selection and nest survival from 2001 to 2010 in Roosevelt County, New Mexico, USA at 2 spatial scales (i.e., treatment and microhabitat) in 4 treatments: tebuthiuron with grazing, tebuthiuron without grazing, no tebuthiuron with grazing, and a control of no tebuthiuron and no grazing. Grazing treatment was a short-duration system in which plots were grazed once during the dormant season and once during the growing season. Stocking rate was calculated each season based on measured forage production and applied to remove ≤25% of available herbaceous material per season. At the treatment scale, we compared nest site selection among treatments using 1-way χ2 tests and nest survival among treatments using a priori candidate nest survival models in Program MARK. At the microhabitat scale, we identified important habitat predictors of nest site selection and nest survival using logistic regression and a priori candidate nest survival models in Program MARK, respectively. Females typically used treatments as expected and

  3. Association of Candidate Genes With Submergence Response in Perennial Ryegrass

    Directory of Open Access Journals (Sweden)

    Xicheng Wang

    2017-05-01

    Full Text Available Perennial ryegrass is a popular cool-season grass species due to its high quality for forage and turf. The objective of this study was to identify associations of candidate genes with growth and physiological traits to submergence stress and recovery after de-submergence in a global collection of 94 perennial ryegrass accessions. Accessions varied largely in leaf color, plant height (HT, leaf fresh weight (LFW, leaf dry weight (LDW, and chlorophyll fluorescence (Fv/Fm at 7 days of submergence and in HT, LFW and LDW at 7 days of recovery in two experiments. Among 26 candidate genes tested by various models, single nucleotide polymorphisms (SNPs in 10 genes showed significant associations with traits including 16 associations for control, 10 for submergence, and 8 for recovery. Under submergence, Lp1-SST encoding sucrose:sucrose 1-fructosyltransferase and LpGA20ox encoding gibberellin 20-oxidase were associated with LFW and LDW, and LpACO1 encoding 1-aminocyclopropane-1-carboxylic acid oxidase was associated with LFW. Associations between Lp1-SST and HT, Lp6G-FFT encoding fructan:fructan 6G-fructosyltransferase and Fv/Fm, LpCAT encoding catalase and HT were also detected under submergence stress. Upon de-submergence, Lp1-SST, Lp6G-FFT, and LpPIP1 encoding plasma membrane intrinsic protein type 1 were associated with LFW or LDW, while LpCBF1b encoding C-repeat binding factor were associated with HT. Nine significant SNPs in Lp1-SST, Lp6G-FFT, LpCAT, and LpACO1 resulted in amino acid changes with five substitutions found in Lp1-SST under submergence or recovery. The results indicated that allelic diversity in genes involved in carbohydrate and antioxidant metabolism, ethylene and gibberellin biosynthesis, and transcript factor could contribute to growth variations in perennial ryegrass under submergence stress and recovery after de-submergence.

  4. Revegetation of wellsite disturbances on Fescue Prairie in east-central Alberta

    International Nuclear Information System (INIS)

    Woosaree, J.; Puhl, M.

    1999-01-01

    It has been observed that past methods of revegetating disturbed land in Alberta by using commercially-available species of grasses has had limited success in terms of biodiversity, the reason being that commercial forage species are highly competitive, and as such not only prevented the original prairie species from returning to reclaimed sites, but in some cases they have migrated from reclaimed sites and invaded surrounding native prairie. Alfalfa, crested wheatgrass, Kentucky bluegrass and Canada bluegrass are believed to be the most invasive of these commercially available species. Because their use in the past has resulted in landscape fragmentation, they are not recommended for use on wellsites located on native prairie. The limited mix of available native grass cultivars also have had limited success in increasing species diversity. Cross seeding has been suggested as one method for reducing the effect of inter-specific competition on the species emergence. However, the general view of government and industry is that improved methods of revegetation of wellsite disturbances and new guidelines for determining reclamation success are required to establish more ecologically compatible plant communities on well site disturbances 4 refs., 1 tab., 3 figs

  5. Restoring sand shinnery oak prairies with herbicide and grazing in New Mexico

    Science.gov (United States)

    Zavaleta, Jennifer C.; Haukos, David A.; Grisham, Blake A.; Boal, Clint W.; Dixon, Charles

    2016-01-01

    Sand shinnery oak (Quercus havardii) prairies are increasingly disappearing and increasingly degraded in the Southern High Plains of Texas and New Mexico. Restoring and managing sand shinnery oak prairie can support biodiversity, specific species of conservation concern, and livestock production. We measured vegetation response to four treatment combinations of herbicide (tebuthiuron applied at 0.60 kg/ha) and moderate-intensity grazing (50% removal of annual herbaceous production) over a 10-year period in a sand shinnery oak prairie of eastern New Mexico. We compared the annual vegetation response to the historical climax plant community (HCPC) as outlined by the U.S. Department of Agriculture Ecological Site Description. From 2 to 10 years postapplication, tebuthiuron-treated plots had reduced shrub cover with twice as much forb and grass cover as untreated plots. Tebuthiuron-treated plots, regardless of the presence of grazing, most frequently met HCPC. Tebuthiuron and moderate-intensity grazing increased vegetation heterogeneity and, based on comparison of the HCPC, successfully restored sand shinnery oak prairie to a vegetation composition similar to presettlement.

  6. Nesting ecology and nest survival of lesser prairie-chickens on the Southern High Plains of Texas

    Science.gov (United States)

    Grisham, Blake A.; Borsdorf, Philip K.; Boal, Clint W.; Boydston, Kathy K.

    2014-01-01

    The decline in population and range of lesser prairie-chickens (Tympanuchus pallidicinctus) throughout the central and southern Great Plains has raised concerns considering their candidate status under the United States Endangered Species Act. Baseline ecological data for lesser prairie-chickens are limited, especially for the shinnery oak-grassland communities of Texas. This information is imperative because lesser prairie-chickens in shinnery oak grasslands occur at the extreme southwestern edge of their distribution. This geographic region is characterized by hot, arid climates, less fragmentation, and less anthropogenic development than within the remaining core distribution of the species. Thus, large expanses of open rangeland with less anthropogenic development and a climate that is classified as extreme for ground nesting birds may subsequently influence nest ecology, nest survival, and nest site selection differently compared to the rest of the distribution of the species. We investigated the nesting ecology of 50 radio-tagged lesser prairie-chicken hens from 2008 to 2011 in the shinnery oak-grassland communities in west Texas and found a substantial amount of inter-annual variation in incubation start date and percent of females incubating nests. Prairie-chickens were less likely to nest near unimproved roads and utility poles and in areas with more bare ground and litter. In contrast, hens selected areas dominated by grasses and shrubs and close to stock tanks to nest. Candidate models including visual obstruction best explained daily nest survival; a 5% increase in visual obstruction improved nest survival probability by 10%. The model-averaged probability of a nest surviving the incubation period was 0.43 (SE = 0.006; 95% CI: 0.23, 0.56). Our findings indicate that lesser prairie-chicken reproduction during our study period was dynamic and was correlated with seasonal weather patterns that ultimately promoted greater grass growth earlier in the

  7. Introducing perennial biomass crops into agricultural landscapes to address water quality challenges and provide other environmental services: Integrating perennial bioenergy crops into agricultural landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Cacho, J. F. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Negri, M. C. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Zumpf, C. R. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Campbell, P. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA

    2017-11-29

    The world is faced with a difficult multiple challenge of meeting nutritional, energy, and other basic needs, under a limited land and water budget, of between 9 and 10 billion people in the next three decades, mitigating impacts of climate change, and making agricultural production resilient. More productivity is expected from agricultural lands, but intensification of production could further impact the integrity of our finite surface water and groundwater resources. Integrating perennial bioenergy crops in agricultural lands could provide biomass for biofuel and potential improvements on the sustainability of commodity crop production. This article provides an overview of ways in which research has shown that perennial bioenergy grasses and short rotation woody crops can be incorporated into agricultural production systems with reduced indirect land use change, while increasing water quality benefits. Current challenges and opportunities as well as future directions are also highlighted.

  8. Ecological consequences of shifting the timing of burning tallgrass prairie.

    Directory of Open Access Journals (Sweden)

    E Gene Towne

    Full Text Available In the Kansas Flint Hills, grassland burning is conducted during a relatively narrow window because management recommendations for the past 40 years have been to burn only in late spring. Widespread prescribed burning within this restricted time frame frequently creates smoke management issues downwind. A potential remedy for the concentrated smoke production in late spring is to expand burning to times earlier in the year. Yet, previous research suggested that burning in winter or early spring reduces plant productivity and cattle weight gain while increasing the proportion of undesirable plant species. In order to better understand the ecological consequences of burning at different times of the year, plant production and species abundance were measured for 20 years on ungrazed watersheds burned annually in autumn, winter, or spring. We found that there were no significant differences in total grass production among the burns on either upland or lowland topographic positions, although spring burned watersheds had higher grass culm production and lower forb biomass than autumn and winter burned watersheds. Burning in autumn or winter broadened the window of grass productivity response to precipitation, which reduces susceptibility to mid-season drought. Burning in autumn or winter also increased the phenological range of species by promoting cool-season graminoids without a concomitant decrease in warm-season grasses, potentially widening the seasonal window of high-quality forage. Incorporating autumn and winter burns into the overall portfolio of tallgrass prairie management should increase the flexibility in managing grasslands, promote biodiversity, and minimize air quality issues caused by en masse late-spring burning with little negative consequences for cattle production.

  9. Song and Male Quality in Prairie Warblers

    Science.gov (United States)

    Bruce E. Byers; Michael E. Akresh; David I. King; W. Koenig

    2016-01-01

    To determine if the songs of male prairie warblers could potentially reveal to female listeners information about the quality of singers, we compared various aspects of prairie warbler song structure and performance to attributes that might reflect a male singer's potential to enhance the fitness of his mate. We found that all the tested male attributes—arrival...

  10. Plant litter effects on soil nutrient availability and vegetation dynamics: changes that occur when annual grasses invade shrub-steppe communities

    Science.gov (United States)

    Sheel Bansal; Roger L. Sheley; Bob Blank; Edward A. Vasquez

    2014-01-01

    Changes in the quantity and quality of plant litter occur in many ecosystems as they are invaded by exotic species, which impact soil nutrient cycling and plant community composition. Such changes in sagebrush-steppe communities are occurring with invasion of annual grasses (AG) into a perennial grass (PG) dominated system. We conducted a 5-year litter manipulation...

  11. Germination timing and rate of locally collected western wheatgrass and smooth brome grass: the role of collection site and light sensitivity along a riparian corridor

    Science.gov (United States)

    The ecological integrity of riparian areas is reduced by biological plant invaders like smooth brome grass (Bromus inermis). Smooth brome actively invades recently disturbed riparian zones by its high seed production and fast seedling establishment. Restoring native perennial grasses to these regio...

  12. Black-tailed prairie dog status and future conservation planning

    Science.gov (United States)

    Daniel W. Mulhern; Craig J. Knowles

    1997-01-01

    The black-tailed prairie dog is one of five prairie dog species estimated to have once occupied up to 100 million ha or more in North America. The area occupied by black-tailed prairie dogs has declined to approximately 2% of its former range. Conversion of habitat to other land uses and widespread prairie dog eradication efforts combined with sylvatic plague,

  13. The prairie dog as a keystone species

    Science.gov (United States)

    Kotliar, Natasha B.; Miller, Brian J.; Reading, Richard P.; Clark, Timothy W.; Hoogland, John L.

    2006-01-01

    The prairie dog has a pronounced impact on its grassland ecosystem (King 1955; Uresk and Bjugstad 1983; Miller et al. 1994; Society for Conservation Biology 1994; Wuerthner 1997; Johnsgard 2005). They maintain short vegetation by their grazing and by selective removal of tall plants and shrubs; provide shelter, foraging grounds, and nesting habitat for a diverse array of animals; serve as prey for many predators; and alter soil chemistry.Do these impacts mean that the prairie dog is a keystone species? To investigate, we first scrutinize the definition for a keystone species. We then document both vertebrates and invertebrates that associate with prairie dogs and their colony-sites. We examine ecosystem processes at colony-sites, and then assess whether the prairie dog is a legitimate keystone species. Finally, we explore the implications of keystone status for the conservation of prairie dogs.

  14. Functional consequences of climate change-induced plant species loss in a tallgrass prairie.

    Science.gov (United States)

    Craine, Joseph M; Nippert, Jesse B; Towne, E Gene; Tucker, Sally; Kembel, Steven W; Skibbe, Adam; McLauchlan, Kendra K

    2011-04-01

    Future climate change is likely to reduce the floristic diversity of grasslands. Yet the potential consequences of climate-induced plant species losses for the functioning of these ecosystems are poorly understood. We investigated how climate change might alter the functional composition of grasslands for Konza Prairie, a diverse tallgrass prairie in central North America. With species-specific climate envelopes, we show that a reduction in mean annual precipitation would preferentially remove species that are more abundant in the more productive lowland positions at Konza. As such, decreases in precipitation could reduce productivity not only by reducing water availability but by also removing species that inhabit the most productive areas and respond the most to climate variability. In support of this prediction, data on species abundance at Konza over 16 years show that species that are more abundant in lowlands than uplands are preferentially reduced in years with low precipitation. Climate change is likely to also preferentially remove species from particular functional groups and clades. For example, warming is forecast to preferentially remove perennials over annuals as well as Cyperaceae species. Despite these predictions, climate change is unlikely to unilaterally alter the functional composition of the tallgrass prairie flora, as many functional traits such as physiological drought tolerance and maximum photosynthetic rates showed little relationship with climate envelope parameters. In all, although climatic drying would indirectly alter grassland productivity through species loss patterns, the insurance afforded by biodiversity to ecosystem function is likely to be sustained in the face of climate change.

  15. Important Considerations When Choosing Forage Grasses - Research Developments on Quality and Management

    Science.gov (United States)

    Seasonal changes in forage productivity and nutritive value will influence pasture management and ration balancing decisions by the producer. We determined seasonal yield and quality changes in the leaf and stem fraction of 10 temperate perennial grasses at two Wisconsin locations. After reaching ...

  16. Comparison of signaling interactions determining annual and perennial plant growth in response to low temperature

    Directory of Open Access Journals (Sweden)

    Astrid eWingler

    2015-01-01

    Full Text Available Low temperature inhibits plant growth despite the fact that considerable rates of photosynthetic activity can be maintained. Instead of lower rates of photosynthesis, active inhibition of cell division and expansion is primarily responsible for reduced growth. This results in sink limitation and enables plants to accumulate carbohydrates that act as compatible solutes or are stored throughout the winter to enable re-growth in spring. Regulation of growth in response to temperature therefore requires coordination with carbon metabolism, e.g. via the signaling metabolite trehalose-6-phosphate. The phytohormones gibberellins (GA and jasmonate (JA play an important role in regulating growth in response to temperature. Growth restriction at low temperature is mainly mediated by DELLA proteins, whose degradation is promoted by GA. For annual plants, it has been shown that the GA/DELLA pathway interacts with JA signaling and C-repeat binding factor (CBF dependent cold acclimation, but these interactions have not been explored in detail for perennials. Growth regulation in response to seasonal factors is, however, particularly important in perennials, especially at high latitudes. In autumn, growth cessation in trees is caused by shortening of the daylength in interaction with phytohormone signaling. In perennial grasses seasonal differences in the sensitivity to GA may enable enhanced growth in spring. This review provides an overview of the signaling interactions that determine plant growth at low temperature and highlights gaps in our knowledge, especially concerning the seasonality of signaling responses in perennial plants.

  17. Des broussailles dans les prairies alpines

    Directory of Open Access Journals (Sweden)

    Olivier Camacho

    2009-03-01

    Full Text Available Landscape closing due to the decline in agricultural activity is considered to be a major problem in the Alps. Abondance Valley provides a good example of this phenomenon and is also representative of a paradox commonly found in the Northern French Alps: the mountainsides and alpine pastures are still used, whereas they are becoming increasingly afforested. Environmental conditions play a major role in the localisation of agricultural land uses, but they are not sufficient to explain why pastures still in use are being invaded by shrub. Even if cutting makes it possible to effectively control the encroachment by woody species, this is not true for uncut pastures where grazing is not able to keep up with grass production. This situation is repeated every year and is the likely cause of the colonisation by woody species. To ensure their forage system and to simplify their work, farmers tend to establish grazing units that are oversized in relation to the needs of their animals. They implement compensatory practices that consist of mechanical maintenance as a complement to grazing to limit the dynamics of woody species. These labour-intensive practices are not used on all of the pastures. The analysis of farmers’ practices by agronomists is therefore a useful complement to studies of physical and socio-economic environments, at the level of the grazed field as well as at that of the valley as a whole.La dégradation des paysages par suite du recul de l’activité agricole est considérée comme un enjeu majeur dans les Alpes. La vallée d’Abondance illustre bien ce phénomène de fermeture de l’espace mais elle est en outre représentative d’un paradoxe assez répandu dans les Alpes du nord françaises : les versants et les alpages sont encore exploités et pourtant ils se boisent progressivement. Les conditions de milieux jouent un rôle majeur sur la localisation des usages agricoles de l'espace, mais elles ne peuvent pas suffire pour

  18. Recent Progress in Perennial Buckwheat Development

    Directory of Open Access Journals (Sweden)

    Qing-Fu Chen

    2018-02-01

    Full Text Available Grains in the genus Fagopyrum have benefits to human health and are an excellent gluten-free raw material. Of all cereal foods, this genus has the highest total content of amino-acid nutrients necessary for humans; nutrients that are resistant to digestion (protein and starch resulting in their sustained release; higher dietary fiber content than key cereals, and is rich in a special healthy ingredient (flavonoids. Fagopyrum includes 24 species of which five are perennial. Among them, golden buckwheat (F.cymosum complex is the most important perennial buckwheat, which is not only used in Chinese medicine, but also has great potential in healthy food crop. In order to provide some clues for perennial crop studies and their industry development, this paper presents the state of perennial buckwheat research in terms of taxonomy; natural chemical products and pharmacological and health functions; genetics and evolution; breeding; and product development and utilization. The great advances such as successful interspecific crossing and its subsequent new perennial buckwheat varieties will speed up the development of the perennial buckwheat industry.

  19. Prairie Change Analysis 1991-2008

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset displays the results of a prairie/savanna change analysis study completed in May 2010. The area reviewed consists of 1,521 sites identified by Minnesota...

  20. Overview of the 2013 FireFlux II grass fire field experiment

    Science.gov (United States)

    C.B. Clements; B. Davis; D. Seto; J. Contezac; A. Kochanski; J.-B. Fillipi; N. Lareau; B. Barboni; B. Butler; S. Krueger; R. Ottmar; R. Vihnanek; W.E. Heilman; J. Flynn; M.A. Jenkins; J. Mandel; C. Teske; D. Jimenez; J. O' Brien; B. Lefer

    2014-01-01

    In order to better understand the dynamics of fire-atmosphere interactions and the role of micrometeorology on fire behaviour the FireFlux campaign was conducted in 2006 on a coastal tall-grass prairie in southeast Texas, USA. The FireFlux campaign dataset has become the international standard for evaluating coupled fire-atmosphere model systems. While FireFlux is one...

  1. Investigating the Sustainability of Perennial Agriculture

    Science.gov (United States)

    Sutherlin, C. E.; Brunsell, N. A.; De Oliveira, G.; Crews, T.; Vico, G.

    2017-12-01

    The changing climate leads to uncertainties concerning the sustainability of certain agricultural resources, and with the additional stresses of an increasing global population, uncertainty in food security will greatly increase. To adhere to future food demands in the face of this changing climate, perennial agriculture has been a proposed solution. However, it is equally important to assure that perennial agriculture is not negatively affecting the climate in exchange for this proposed more robust food source. We chose to examine the interactions between perennial and annual agricultural crops by focusing on the efficiency of exchanges with the atmosphere. This is done using the omega decoupling factor for 4 different sites as a way of quantifying the contributions of radiation and stomatal conductance over the resulting water and carbon cycles. This gives us an indication of how the plant canopy is interacting with, and influencing the local microclimate. Ultimately, this should give us an indication of the ability of perennial crops to aid in the climate mitigation process. We hypothesized that the perennial site chosen would have omega values more similar to the omega values of a natural grassland rather than an annual crop site. Using AmeriFlux towers to determine the canopy values needed to calculate the omega decoupling factor, we focused on the Kernza perennial crops being grown at the Land Institute in Salina, Kansas (KLS), in comparison to a natural grassland in Manhattan, Kansas (KON), a typical land cover model in Lawrence, Kansas (KFS), and an annual crop site in Lamont, Oklahoma (ARM). These results will allow us to move forward in the investigation of perennial crops as a sustainable food source.

  2. Phytostabilisation potential of lemon grass (Cymbopogon flexuosus (Nees ex Stend) Wats) on iron ore tailings.

    Science.gov (United States)

    Mohanty, M; Dhal, N K; Patra, P; Das, B; Reddy, P S R

    2012-01-01

    The present pot culture study was carried out for the potential phytostabilisation of iron ore tailings using lemon grass (Cymbopogon flexuosus) a drought tolerant, perennial, aromatic grass. Experiments have been conducted by varying the composition of garden soil (control) with iron ore tailings. The various parameters, viz. growth of plants, number of tillers, biomass and oil content of lemon grass are evaluated. The studies have indicated that growth parameters of lemon grass in 1:1 composition of garden soil and iron ore tailings are significantly more (-5% increase) compared to plants grown in control soil. However, the oil content of lemon grass in both the cases more or less remained same. The results also infer that at higher proportion of tailings the yield of biomass decreases. The studies indicate that lemongrass with its fibrous root system is proved to be an efficient soil binder by preventing soil erosion.

  3. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    DEFF Research Database (Denmark)

    Tomaszewski, Céline; Byrne, Stephen; Foito, Alexandra

    2012-01-01

    Perennial ryegrass is the principal forage grass species used in temperate agriculture. In recent years, significant efforts have been made to develop molecular marker strategies to allow cost-effective characterization of a large number of loci simultaneously. One such strategy involves using DAr......T markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used...

  4. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland?

    Science.gov (United States)

    Canty, Mary J; Fogarty, Ursula; Sheridan, Michael K; Ensley, Steve M; Schrunk, Dwayne E; More, Simon J

    2014-01-01

    Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as 'ergot alkaloid intoxication'. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of a

  5. Review of literature on perennial peanut (Arachis pintoi) as potential cover crop in the tropics

    OpenAIRE

    Kartika, J.G.; Reyes, Manuel R.; Susila, Anas D.

    2007-01-01

    The use of living mulch as a substitute for plastic mulch is increasing in the tropics as researchers have gradually shifted their attention to organic farming systems. Arachis pintoi is a perennial plant and a member of the leguminosae family. A. pintoi has good potential for use as a living mulch in association with vegetables, trees, or grass (as a pasture) because of its ability to fix nitrogen from the atmosphere and to grow in heavy shade. This work, based on fact sheets, journals and t...

  6. Vegetation of wetlands of the prairie pothole region

    Science.gov (United States)

    Kantrud, H.A.; Millar, J.B.; Van Der Valk, A.G.; van der Valk, A.

    1989-01-01

    Five themes dominate the literature dealing with the vegetation of palustrine and lacustrine wetlands of the prairie pothole region: environmental conditions (water or moisture regime, salinity), agricultural disturbances (draining, grazing, burning, sedimentation, etc.), vegetation dynamics, zonation patterns, and classification of the wetlands.The flora of a prairie wetland is a function of its water regime, salinity, and disturbance by man. Within a pothole, water depth and duration determines distribution of species. In potholes deep enough to have standing water even during droughts, the central zone will be dominated by submersed species (open water). In wetlands that go dry during periods of drought or annually, the central zone will be dominated by either tall emergent species (deep marsh) or midheight emergents (shallow marsh), respectively. Potholes that are only flooded briefly in the spring are dominated by grasses, sedges, and forbs (wet meadow). Within a pothole, the depth of standing water in the deepest, usually central, part of the basin determines how many zones will be present. Lists of species associated with different water regimes and salinity levels are presented.Disturbances due to agricultural activities have impacted wetlands throughout the region. Drainage has eliminated many potholes, particularly in the southern and eastern parts of the region. Grazing, mowing, and burning have altered the composition of pothole vegetation. The composition of different vegetation types impacted by grazing, haying, and cultivation is presented in a series of tables. Indirect impacts of agriculture (increased sediment, nutrient, and pesticide inputs) are widespread over the region, but their impacts on the vegetation have never been studied.Because of the periodic droughts and wet periods, many palustrine and lacustrine wetlands undergo vegetation cycles associated with water-level changes produced by these wet-dry cycles. Periods of above normal

  7. Seasonal Variation of Provitamin D2 and Vitamin D2 in Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Didion, Thomas; Smedsgaard, Jørn

    2011-01-01

    Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light. Six varieties of perennial ryegrass (Lolium perenne L.) were harvested four times during the season, and the contents of vitamin D(2) and ergosterol were analyzed by a sensitive and selective liquid...... chromatography tandem mass spectrometry method. Weather factors were recorded, and a principal component analysis was performed to study which factors were important for the formation of vitamin D(2). The results suggest that a combination of weather factors is involved and that the contents of ergosterol...... and vitamin D(2) change more than a factor of 10 during the season. These results demonstrate that grass potentially can be a significant source of vitamin D for grazing animals and animals fed on silage and hay....

  8. Model estimation of land-use effects on water levels of northern Prairie wetlands

    Science.gov (United States)

    Voldseth, R.A.; Johnson, W.C.; Gilmanov, T.; Guntenspergen, G.R.; Millett, B.V.

    2007-01-01

    Wetlands of the Prairie Pothole Region exist in a matrix of grassland dominated by intensive pastoral and cultivation agriculture. Recent conservation management has emphasized the conversion of cultivated farmland and degraded pastures to intact grassland to improve upland nesting habitat. The consequences of changes in land-use cover that alter watershed processes have not been evaluated relative to their effect on the water budgets and vegetation dynamics of associated wetlands. We simulated the effect of upland agricultural practices on the water budget and vegetation of a semipermanent prairie wetland by modifying a previously published mathematical model (WETSIM). Watershed cover/land-use practices were categorized as unmanaged grassland (native grass, smooth brome), managed grassland (moderately heavily grazed, prescribed burned), cultivated crops (row crop, small grain), and alfalfa hayland. Model simulations showed that differing rates of evapotranspiration and runoff associated with different upland plant-cover categories in the surrounding catchment produced differences in wetland water budgets and linked ecological dynamics. Wetland water levels were highest and vegetation the most dynamic under the managed-grassland simulations, while water levels were the lowest and vegetation the least dynamic under the unmanaged-grassland simulations. The modeling results suggest that unmanaged grassland, often planted for waterfowl nesting, may produce the least favorable wetland conditions for birds, especially in drier regions of the Prairie Pothole Region. These results stand as hypotheses that urgently need to be verified with empirical data.

  9. Perrenial Grasses for Sustainable European Protein Production

    DEFF Research Database (Denmark)

    Jørgensen, Uffe; Lærke, Poul Erik

    2016-01-01

    reduction goals for agriculture. Denmark has an especially vulnerable aquatic environment due to sandy soils, a long coast line, and high precipitation. Thus, fulfilling the WFD means some areas must halve their nitrate leaching, and radical changes are required to reduce losses while maintaining profitable...... crop production. National scenarios show that up to ten million tonnes of additional biomass can be sourced in Denmark without reducing food production or increasing the area under cultivation if a biorefinery industry is established. In one of the scenarios optimized for additional environmental...... in the “environment” scenario. This scenario was achieved by converting approx. 9 % of agricultural land from annual crops into perennial grass. New experimental results support the anticipated increase in total biomass yield and reduction in nitrate leaching, when converting land currently used for grain crop...

  10. Comparative growth analysis of cool- and warm-season grasses in a cool-temperate environment

    International Nuclear Information System (INIS)

    Belesky, D.P.; Fedders, J.M.

    1995-01-01

    Using both cool-season (C3) and warm-season (C4) species is a viable means of optimizing herbage productivity over varying climatic conditions in temperate environments. Despite well-documented differences in water, N, and radiation use, no consistent evidence demonstrates productivity differences among C3 and C4 perennial grass species under identical management. A field study was conducted to determine relative growth rates (RGR), nitrogen productivity (NP), and mean radiation productivity (RP) (dry matter production as a function of incident radiation) of cool- and warm-season grasses managed identically. Results were used to identify management practices thd could lead to optimal productivity in combinations or mixtures of cool- and warm-season grasses. Dry matter yields of warm-season grasses equaled or surpassed those of cool-season grasses, despite a 40% shorter growth interval. Certain cool- and warm-season grasses appear to be suitable for use in mixtures, based on distribution of herbage production; however, actual compatibility may be altered by defoliation management. Relative growth rates varied among years and were about 40% lower for canopies clipped to a 10-cm residue height each time 20-cm of growth accumulated compared with other treatments. The RGR of warm-season grasses was twice that of cool-season grasses Nitrogen productivity (g DM g-1 N d -1) and mean radiation productivity (g DM MJ-1) for warm-season grasses was also more than twice that of cool-season grasses. Radiation productivity of cool-season grasses was dependent on N, while this was not always the case for warm-season grasses. The superior production capability of certain warm-season compared with cool-season grasses in a cool-temperate environment can be sustained under a range of defoliation treatments and demonstrates suitability for use in frequently defoliated situations

  11. resistance of napier grass clones to napier grass stunt disease

    African Journals Online (AJOL)

    ACSS

    Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease. (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.

  12. Resistance of Napier grass clones to Napier grass Stunt Disease ...

    African Journals Online (AJOL)

    Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.

  13. A novel method to characterize silica bodies in grasses.

    Science.gov (United States)

    Dabney, Clemon; Ostergaard, Jason; Watkins, Eric; Chen, Changbin

    2016-01-01

    The deposition of silicon into epidermal cells of grass species is thought to be an important mechanism that plants use as a defense against pests and environmental stresses. There are a number of techniques available to study the size, density and distribution pattern of silica bodies in grass leaves. However, none of those techniques can provide a high-throughput analysis, especially for a great number of samples. We developed a method utilizing the autofluorescence of silica bodies to investigate their size and distribution, along with the number of carbon inclusions within the silica bodies of perennial grass species Koeleria macrantha. Fluorescence images were analyzed by image software Adobe Photoshop CS5 or ImageJ that remarkably facilitated the quantification of silica bodies in the dry ash. We observed three types of silica bodies or silica body related mineral structures. Silica bodies were detected on both abaxial and adaxial epidermis of K. macrantha leaves, although their sizes, density, and distribution patterns were different. No auto-fluorescence was detected from carbon inclusions. The combination of fluorescence microscopy and image processing software displayed efficient utilization in the identification and quantification of silica bodies in K. macrantha leaf tissues, which should applicable to biological, ecological and geological studies of grasses including forage, turf grasses and cereal crops.

  14. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    Science.gov (United States)

    Gherardi, Laureano A.; Sala, Osvaldo E.

    2015-01-01

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society. PMID:26417095

  15. A comparison of cellulosic fuel yields and separated soil-surface CO2 fluxes in maize and prairie biofuel cropping systems

    Science.gov (United States)

    Nichols, Virginia A.

    It has been suggested that strategic incorporation of perennial vegetation into agricultural landscapes could provide ecosystem services while maintaining agricultural productivity. To evaluate potential use of prairie as a Midwestern cellulosic feedstock, we investigated theoretical cellulosic fuel yields, as well as soil-surface carbon dioxide emissions of prairie-based biofuel systems as compared to maize-based systems on fertile soils in Boone County, IA, USA. Investigated systems were: a maize-soybean rotation grown for grain only, continuous maize grown for grain and stover both with and without a winter rye cover crop, and a 31-species reconstructed prairie grown with and without spring nitrogen fertilization for fall-harvested biomass. From 2009-2013, the highest producing system was N-fertilized prairie, averaging 10.4 Mg ha -1 yr-1 above-ground biomass with average harvest removals of 7.8 Mg ha-1 yr-1. The unfertilized prairie produced 7.4 Mg ha-1 yr-1, averaging harvests of 5.3 Mg ha-1 yr-1. Lowest cellulosic biomass harvests were realized from continuous maize systems, averaging 3.5 Mg ha -1 yr-1 when grown with, and 3.7 Mg ha-1 yr-1 when grown without a winter rye cover crop, respectively. Un-fertilized prairie biomass and maize stover had equivalent dietary conversion ratios at 330 g ethanol kg-1 dry biomass, but N-fertilized prairie was lower at 315. Over four years prairie systems averaged 1287 L cellulosic ethanol ha-1 yr-1 more than maize systems, with fertilization increasing prairie ethanol production by 865 L ha-1 yr-1. Harvested biomass accounted for >90% of ethanol yield variation. A major hurdle in carbon cycling studies is the separation of the soil-surface CO2 flux into its respective components. From 2012-2013 we used a shading method to separate soil-surface CO2 resulting from oxidation of soil organic matter and CO2 derived from live-root activity in three systems: unfertilized prairie, N-fertilized prairie, and continuous maize

  16. Soil change induced by prairie dogs across three ecological sites

    Science.gov (United States)

    Prairie dogs (Cynomys spp.) can influence vegetation dynamics and landscape hydrology by altering soil properties, yet few studies have evaluated soil responses to prairie dog activities across a range of soil types. This study was conducted to quantify prairie dog effects on soil properties within...

  17. Grass Rooting the System

    Science.gov (United States)

    Perlman, Janice E.

    1976-01-01

    Suggests a taxonomy of the grass roots movement and gives a general descriptive over view of the 60 groups studied with respect to origin, constituency, size, funding, issues, and ideology. (Author/AM)

  18. Root Characteristics of Perennial Warm-Season Grasslands Managed for Grazing and Biomass Production

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2013-07-01

    Full Text Available Minirhizotrons were used to study root growth characteristics in recently established fields dominated by perennial C4-grasses that were managed either for cattle grazing or biomass production for bioenergy in Virginia, USA. Measurements over a 13-month period showed that grazing resulted in smaller total root volumes and root diameters. Under biomass management, root volume was 40% higher (49 vs. 35 mm3 and diameters were 20% larger (0.29 vs. 0.24 mm compared to grazing. While total root length did not differ between grazed and biomass treatments, root distribution was shallower under grazed areas, with 50% of total root length in the top 7 cm of soil, compared to 41% in ungrazed exclosures. These changes (i.e., longer roots and greater root volume in the top 10 cm of soil under grazing but the reverse at 17–28 cm soil depths were likely caused by a shift in plant species composition as grazing reduced C4 grass biomass and allowed invasion of annual unsown species. The data suggest that management of perennial C4 grasslands for either grazing or biomass production can affect root growth in different ways and this, in turn, may have implications for the subsequent carbon sequestration potential of these grasslands.

  19. Accuracy of Genomic Prediction in a Commercial Perennial Ryegrass Breeding Program

    Directory of Open Access Journals (Sweden)

    Dario Fè

    2016-11-01

    Full Text Available The implementation of genomic selection (GS in plant breeding, so far, has been mainly evaluated in crops farmed as homogeneous varieties, and the results have been generally positive. Fewer results are available for species, such as forage grasses, that are grown as heterogenous families (developed from multiparent crosses in which the control of the genetic variation is far more complex. Here we test the potential for implementing GS in the breeding of perennial ryegrass ( L. using empirical data from a commercial forage breeding program. Biparental F and multiparental synthetic (SYN families of diploid perennial ryegrass were genotyped using genotyping-by-sequencing, and phenotypes for five different traits were analyzed. Genotypes were expressed as family allele frequencies, and phenotypes were recorded as family means. Different models for genomic prediction were compared by using practically relevant cross-validation strategies. All traits showed a highly significant level of genetic variance, which could be traced using the genotyping assay. While there was significant genotype × environment (G × E interaction for some traits, accuracies were high among F families and between biparental F and multiparental SYN families. We have demonstrated that the implementation of GS in grass breeding is now possible and presents an opportunity to make significant gains for various traits.

  20. Evaluating poverty grass (Danthonia spicata L.) for use in tees, fairways, or rough areas in golf courses in the midwest

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; Brad Fresenburg; J.W. Van Sambeek

    2007-01-01

    Poverty grass (Danthonia spicata L.), a native, cool-season perennial bunchgrass with wide distribution in the United States, is being evaluated for its suitability for use on golf courses. The goal is to identify practices to improve seed germination and successfully establish field plots as monocultures or with other native species to mimic natural...

  1. Common garden comparisons of reproductive, forage and weed suppression potential of rangeland rehabilitation grasses of the Great Basin

    Science.gov (United States)

    Common garden experiments are a means to remove environmental effects. Using 8 species of perennial rangeland grasses, we established a common garden (3 reps x28 plants = 84 plants/species). We found that ‘Hycrest’ crested wheatgrass (Agropyron cristatum) and bluebunch wheatgrass (Pseudoroegneria sp...

  2. Delayed chlorophyll a fluorescence, MR 820, and gas exchange changes in perennial ryegrass under salt stress

    Energy Technology Data Exchange (ETDEWEB)

    Dąbrowski, P., E-mail: piotr_dabrowski@sggw.pl [Department of Environmental Improvement, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Kalaji, M.H., E-mail: hazem@kalaji.pl [Department of Plant Physiology, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); SI TECHNOLOGY Sp. z o. o., Górczewska 226C/26, 01-460 Warsaw (Poland); Baczewska, A.H., E-mail: a.baczewska@obpan.pl [Polish Academy of Sciences Botanical Garden-Center for Biological Diversity Conservation in Powsin, 2 Prawdziwka St., 02-973 Warsaw (Poland); Pawluśkiewicz, B. [Department of Environmental Improvement, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Mastalerczuk, G., E-mail: grazyna_mastalerczuk@sggw.pl [Department of Agronomy, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Borawska-Jarmułowicz, B., E-mail: barbara_borawska_jarmulowicz@sggw.pl [Department of Agronomy, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Paunov, M. [Department Biophysics and Radiobiology, St. Kl. Ohridski Sofia University, 8 Dragan Tsankov Blvd., 1164 Sofia (Bulgaria); Goltsev, V., E-mail: goltsev@biofac.uni-sofia.bg [Department Biophysics and Radiobiology, St. Kl. Ohridski Sofia University, 8 Dragan Tsankov Blvd., 1164 Sofia (Bulgaria)

    2017-03-15

    Perennial ryegrass (Lolium perenne L.) is one of the more popular grass species in Europe. It is commonly used for starting lawns in urban areas, where plant growth is limited by many environmental conditions. The contamination of soils by salt is one of the major problems in urban green areas, as well as in natural areas. The basic aim of this study is to provide a detailed in vivo analysis of the changes in the delayed chlorophyll fluorescence and MR 820 signals (induced by salt stress) of two lawn varieties of perennial ryegrass, and to find out if there are correlations between these parameters and gas exchange. Two lawn varieties of Lolium perenne L. were used: Nira and Roadrunner. Salinization was performed at 8 weeks after sowing by adding NaCl in water solution (0, 0.15, and 0.30 M). There were 8 terms of measurement: 0 h, 24 h, 48 h, 96 h, 144 h, 192 h, 240 h, and 288 h after salinization. Our results showed that delayed fluorescence is a tool that can bring completely new opportunities for detecting stress in plants caused by salt. Our work allowed us to identify various limitation patterns in the photosynthetic efficiency of perennial ryegrass lawn varieties grown under salt stress conditions. Significant differences between the two tested varieties in response to salt stress were confirmed.

  3. Delayed chlorophyll a fluorescence, MR 820, and gas exchange changes in perennial ryegrass under salt stress

    International Nuclear Information System (INIS)

    Dąbrowski, P.; Kalaji, M.H.; Baczewska, A.H.; Pawluśkiewicz, B.; Mastalerczuk, G.; Borawska-Jarmułowicz, B.; Paunov, M.; Goltsev, V.

    2017-01-01

    Perennial ryegrass (Lolium perenne L.) is one of the more popular grass species in Europe. It is commonly used for starting lawns in urban areas, where plant growth is limited by many environmental conditions. The contamination of soils by salt is one of the major problems in urban green areas, as well as in natural areas. The basic aim of this study is to provide a detailed in vivo analysis of the changes in the delayed chlorophyll fluorescence and MR 820 signals (induced by salt stress) of two lawn varieties of perennial ryegrass, and to find out if there are correlations between these parameters and gas exchange. Two lawn varieties of Lolium perenne L. were used: Nira and Roadrunner. Salinization was performed at 8 weeks after sowing by adding NaCl in water solution (0, 0.15, and 0.30 M). There were 8 terms of measurement: 0 h, 24 h, 48 h, 96 h, 144 h, 192 h, 240 h, and 288 h after salinization. Our results showed that delayed fluorescence is a tool that can bring completely new opportunities for detecting stress in plants caused by salt. Our work allowed us to identify various limitation patterns in the photosynthetic efficiency of perennial ryegrass lawn varieties grown under salt stress conditions. Significant differences between the two tested varieties in response to salt stress were confirmed.

  4. B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass.

    Science.gov (United States)

    Harper, John; Phillips, Dylan; Thomas, Ann; Gasior, Dagmara; Evans, Caron; Powell, Wayne; King, Julie; King, Ian; Jenkins, Glyn; Armstead, Ian

    2018-04-09

    Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.

  5. Environmental Performance of Miscanthus, Switchgrass and Maize: Can C4 Perennials Increase the Sustainability of Biogas Production?

    Directory of Open Access Journals (Sweden)

    Andreas Kiesel

    2016-12-01

    Full Text Available Biogas is considered a promising option for complementing the fluctuating energy supply from other renewable sources. Maize is currently the dominant biogas crop, but its environmental performance is questionable. Through its replacement with high-yielding and nutrient-efficient perennial C4 grasses, the environmental impact of biogas could be considerably improved. The objective of this paper is to assess and compare the environmental performance of the biogas production and utilization of perennial miscanthus and switchgrass and annual maize. An LCA was performed using data from field trials, assessing the impact in the five categories: climate change (CC, fossil fuel depletion (FFD, terrestrial acidification (TA, freshwater eutrophication (FE and marine eutrophication (ME. A system expansion approach was adopted to include a fossil reference. All three crops showed significantly lower CC and FFD potentials than the fossil reference, but higher TA and FE potentials, with nitrogen fertilizer production and fertilizer-induced emissions identified as hot spots. Miscanthus performed best and changing the input substrate from maize to miscanthus led to average reductions of −66% CC; −74% FFD; −63% FE; −60% ME and −21% TA. These results show that perennial C4 grasses and miscanthus in particular have the potential to improve the sustainability of the biogas sector.

  6. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    Science.gov (United States)

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The effects of energy grass plantations on biodiversity. 2nd annual report

    Energy Technology Data Exchange (ETDEWEB)

    Semere, T.; Slater, F.

    2004-07-01

    This report, which covers the year 2003 growing season, is the second annual report about a project to investigate the ecological impact on biodiversity of plantations of biomass grass crops grown in Hertfordshire in the UK. Wildlife monitoring was carried out at five field sites growing the perennial rhizomatous grass crops Miscanthus, reed canary grass and switch grass. The report covers the findings from wildlife surveys for the 2003 season, the final results from the invertebrate identification from the 2002 season, data entry from the 2002 and 2003 seasons, and the continued invertebrate identification during the 2003 season. Butterfly assessments and an evaluation of crop characteristics such as plant height, plant/stem density and biomass yield were also performed. Results are presented with respect to crop field characteristics, pests and diseases, ground flora, ground beetles, birds, small mammals, butterflies and epigeal invertebrates. Plans for the next growing season are outlined.

  8. De novo assembly of the perennial ryegrass transcriptome using an RNA-Seq strategy.

    Directory of Open Access Journals (Sweden)

    Jacqueline D Farrell

    Full Text Available Perennial ryegrass is a highly heterozygous outbreeding grass species used for turf and forage production. Heterozygosity can affect de-Bruijn graph assembly making de novo transcriptome assembly of species such as perennial ryegrass challenging. Creating a reference transcriptome from a homozygous perennial ryegrass genotype can circumvent the challenge of heterozygosity. The goals of this study were to perform RNA-sequencing on multiple tissues from a highly inbred genotype to develop a reference transcriptome. This was complemented with RNA-sequencing of a highly heterozygous genotype for SNP calling.De novo transcriptome assembly of the inbred genotype created 185,833 transcripts with an average length of 830 base pairs. Within the inbred reference transcriptome 78,560 predicted open reading frames were found of which 24,434 were predicted as complete. Functional annotation found 50,890 transcripts with a BLASTp hit from the Swiss-Prot non-redundant database, 58,941 transcripts with a Pfam protein domain and 1,151 transcripts encoding putative secreted peptides. To evaluate the reference transcriptome we targeted the high-affinity K+ transporter gene family and found multiple orthologs. Using the longest unique open reading frames as the reference sequence, 64,242 single nucleotide polymorphisms were found. One thousand sixty one open reading frames from the inbred genotype contained heterozygous sites, confirming the high degree of homozygosity.Our study has developed an annotated, comprehensive transcriptome reference for perennial ryegrass that can aid in determining genetic variation, expression analysis, genome annotation, and gene mapping.

  9. An adaptive approach to invasive plant management on U.S. Fish and Wildlife Service-owned native prairies in the Prairie Pothole Region: decision support under uncertainity

    Science.gov (United States)

    Gannon, Jill J.; Moore, Clinton T.; Shaffer, Terry L.; Flanders-Wanner, Bridgette

    2011-01-01

    Much of the native prairie managed by the U.S. Fish and Wildlife Service (Service) in the Prairie Pothole Region (PPR) is extensively invaded by the introduced cool-season grasses smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). The central challenge to managers is selecting appropriate management actions in the face of biological and environmental uncertainties. We describe the technical components of a USGS management project, and explain how the components integrate and inform each other, how data feedback from individual cooperators serves to reduce uncertainty across the whole region, and how a successful adaptive management project is coordinated and maintained on a large scale. In partnership with the Service, the U.S. Geological Survey is developing an adaptive decision support framework to assist managers in selecting management actions under uncertainty and maximizing learning from management outcomes. The framework is built around practical constraints faced by refuge managers and includes identification of the management objective and strategies, analysis of uncertainty and construction of competing decision models, monitoring, and mechanisms for model feedback and decision selection. Nineteen Service field stations, spanning four states of the PPR, are participating in the project. They share a common management objective, available management strategies, and biological uncertainties. While the scope is broad, the project interfaces with individual land managers who provide refuge-specific information and receive updated decision guidance that incorporates understanding gained from the collective experience of all cooperators.

  10. Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

    Energy Technology Data Exchange (ETDEWEB)

    Koteen, Laura E; Harte, John [Energy and Resources Group, 310 Barrows Hall, University of California, Berkeley, CA 94720 (United States); Baldocchi, Dennis D, E-mail: lkoteen@berkeley.edu [Department of Environmental Science, Policy and Management, 137 Mulford Hall, University of California, Berkeley, CA 94720 (United States)

    2011-10-15

    Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

  11. Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

    Science.gov (United States)

    Koteen, Laura E.; Baldocchi, Dennis D.; Harte, John

    2011-10-01

    Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

  12. Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

    International Nuclear Information System (INIS)

    Koteen, Laura E; Harte, John; Baldocchi, Dennis D

    2011-01-01

    Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

  13. Invasive plants affect prairie soil biology

    Science.gov (United States)

    Non-native or exotic plants often cause ecological and environmental damage in ecosystems where they invade and become established. These invasive plants may be the most serious threat to plant diversity in prairies, especially those in scattered remnants, which may be particularly vulnerable to rap...

  14. Timber resource of Minnesota's Prairie unit, 1977.

    Science.gov (United States)

    Jerold T. Hahn; W. Brad Smith

    1980-01-01

    The fourth inventory of Minnesota's Prairie Unit shows that although commercial forest area decreased 31.7% between 1962 and 1977, growing-stock volume increased 22%. This report gives statistical highlights and contains detailed tables of forest area as well as timber volume, growth, mortality, ownership, and use.

  15. Timber resource of Missouri's Prairie, 1972.

    Science.gov (United States)

    Jerold T. Hahn; Alexander Vasilevsky

    1975-01-01

    The third timber inventory of Missouri's Prairie Forest Survey Unit shows substantial declines in both growing-stock and sawtimber volumes between 1959 and 1972. Commercial forest area declined by one-fifth. Presents highlights and statistics on forest area and timber volume, growth, mortality, ownership, and use in 1972.

  16. The Genetics of Biofuel Traits in Panicum Grasses: Developing a Model System with Diploid Panicum Hallii

    Energy Technology Data Exchange (ETDEWEB)

    Juenger, Thomas [Univ. of Texas, Austin, TX (United States). Dept. of Integrative Biology; Wolfrum, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-07-31

    Our DOE funded project focused on characterizing natural variation in C4 perennial grasses including switchgrass (Panicum virgatum) and Hall’s panicgrass (Panicum hallii). The main theme of our project was to better understand traits linked with plant performance and that impact the utility of plant biomass as a biofuel feedstock. In addition, our project developed tools and resources for studying genetic variation in Panicum hallii. Our project successfully screened both Panicum virgatum and Panicum hallii diverse natural collections for a host of phenotypes, developed genetic mapping populations for both species, completed genetic mapping for biofuel related traits, and helped in the development of genomic resources of Panicum hallii. Together, these studies have improved our understanding of the role of genetic and environmental factors in impacting plant performance. This information, along with new tools, will help foster the improvement of perennial grasses for feedstock applications.

  17. Native Prairie Adaptive Management: a multi region adaptive approach to invasive plant management on Fish and Wildlife Service owned native prairies

    Science.gov (United States)

    Gannon, Jill J.; Shaffer, Terry L.; Moore, Clinton T.

    2013-01-01

    Much of the native prairie managed by the U.S. Fish and Wildlife Service (FWS) in the Prairie Pothole Region (PPR) of the northern Great Plains is extensively invaded by the introduced cool-season grasses, smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). Management to suppress these invasive plants has had poor to inconsistent success. The central challenge to managers is selecting appropriate management actions in the face of biological and environmental uncertainties. In partnership with the FWS, the U.S. Geological Survey (USGS) developed an adaptive decision support framework to assist managers in selecting management actions under uncertainty and maximizing learning from management outcomes. This joint partnership is known as the Native Prairie Adaptive Management (NPAM) initiative. The NPAM decision framework is built around practical constraints faced by FWS refuge managers and includes identification of the management objective and strategies, analysis of uncertainty and construction of competing decision models, monitoring, and mechanisms for model feedback and decision selection. Nineteen FWS field stations, spanning four states of the PPR, have participated in the initiative. These FWS cooperators share a common management objective, available management strategies, and biological uncertainties. Though the scope is broad, the initiative interfaces with individual land managers who provide site-specific information and receive updated decision guidance that incorporates understanding gained from the collective experience of all cooperators. We describe the technical components of this approach, how the components integrate and inform each other, how data feedback from individual cooperators serves to reduce uncertainty across the whole region, and how a successful adaptive management project is coordinated and maintained on a large scale. During an initial scoping workshop, FWS cooperators developed a consensus management objective

  18. GUI development for GRASS GIS

    Directory of Open Access Journals (Sweden)

    Martin Landa

    2007-12-01

    Full Text Available This article discusses GUI development for GRASS GIS. Sophisticated native GUI for GRASS is one of the key points (besides the new 2D/3D raster library, vector architecture improvements, etc. for the future development of GRASS. In 2006 the GRASS development team decided to start working on the new generation of GUI instead of improving the current GUI based on Tcl/Tk.

  19. An arbuscular mycorrhizal fungus and Epichloë festucae var. lolii reduce Bipolaris sorokiniana disease incidence and improve perennial ryegrass growth.

    Science.gov (United States)

    Li, Fang; Guo, Yan'e; Christensen, Michael J; Gao, Ping; Li, Yanzhong; Duan, Tingyu

    2018-02-01

    Leaf spot of perennial ryegrass (Lolium perenne) caused by Bipolaris sorokiniana is an important disease in temperate regions of the world. We designed this experiment to test for the combined effects of the arbuscular mycorrhizal (AM) fungus Claroideoglomus etunicatum and the grass endophyte fungus Epichloë festucae var. lolii on growth and disease occurrence in perennial ryegrass. The results show that C. etunicatum increased plant P uptake and total dry weight and that this beneficial effect was slightly enhanced when in association with the grass endophyte. The presence in plants of both the endophyte and B. sorokiniana decreased AM fungal colonization. Plants inoculated with B. sorokiniana showed the typical leaf spot symptoms 2 weeks after inoculation and the lowest disease incidence was with plants that were host to both C. etunicatum and E. festucae var. lolii. Plants with these two fungi had much higher activity of peroxidases (POD), superoxide dismutase (SOD) and catalase (CAT) and lower values of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ). The AM fungus C. etunicatum and the grass endophyte fungus E. festucae var. lolii have the potential to promote perennial ryegrass growth and resistance to B. sorokiniana leaf spot.

  20. The optimal CO2 concentrations for the growth of three perennial grass species

    OpenAIRE

    Zheng, Yunpu; Li, Fei; Hao, Lihua; Shedayi, Arshad Ali; Guo, Lili; Ma, Chao; Huang, Bingru; Xu, Ming

    2018-01-01

    Background Grasslands are one of the most representative vegetation types accounting for about 20% of the global land area and thus the response of grasslands to climate change plays a pivotal role in terrestrial carbon balance. However, many current climate change models, based on earlier results of the doubling-CO2 experiments, may overestimate the CO2 fertilization effect, and as a result underestimate the potentially effects of future climate change on global grasslands when the atmospher...

  1. Effect of competition and soil quality on root topology of the perennial grass Molinia caerulea

    Czech Academy of Sciences Publication Activity Database

    Janeček, Štěpán; Janečková, P.; Lepš, Jan

    2007-01-01

    Roč. 79, č. 1 (2007), s. 23-32 ISSN 0032-7786 R&D Projects: GA ČR GD206/03/H034 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Keywords : Carex hartmanii * Holcus lanatus * Molinia caerulea * root Subject RIV: EF - Botanics Impact factor: 2.064, year: 2007

  2. Biomass production and water use efficiency in perennial grasses during and after drought stress

    DEFF Research Database (Denmark)

    Sørensen, Kirsten Kørup; Lærke, Poul Erik; Sørensen, Helle Baadsgaard

    2018-01-01

    be suitable for assessment of drought stress. There were indications of positive associations between plants carbon isotope composition and water use efficiency (WUE) as well as DM under well-watered conditions. Compared to control, drought-treated plots showed increased growth in the period after drought...... stress. Thus, the drought events did not affect total biomass production (DMtotal) of the whole growing season. During drought stress and the whole growing season, WUE was higher in drought-treated compared to control plots, so it seems possible to save water without loss of biomass. Across soil types, M......Drought is a great challenge to agricultural production, and cultivation of drought-tolerant or water use-efficient cultivars is important to ensure high biomass yields for bio-refining and bioenergy. Here, we evaluated drought tolerance of four C3 species, Dactylis glomerata cvs. Sevenop and Amba...

  3. Microsatellite markers for the native Texas perennial grass, Panicum hallii (Poaceae).

    Science.gov (United States)

    Lowry, David B; Purmal, Colin T; Meyer, Eli; Juenger, Thomas E

    2012-03-01

    We developed microsatellites for Panicum hallii for studies of gene flow, population structure, breeding experiments, and genetic mapping. Next-generation (454) genomic sequence data were used to design markers. Eighteen robust markers were discovered, 15 of which were polymorphic across six accessions of P. hallii var. hallii. Fourteen of the markers cross-amplified in a P. capillare accession. For the 15 polymorphic markers, the total number of alleles per locus ranged from two to 26 (mean: 11.0) across six populations (11-19 individuals per population). Observed heterozygosity (mean: 0.031) was 13.7 times lower than the expected heterozygosity (mean: 0.426). The deficit of heterozygous individuals is consistent with P. hallii having a high rate of self-fertilization. These markers will be useful for studies in P. hallii and related species.

  4. Optimizing on-farm pretreatment of perennial grasses for fuel ethanol production.

    Science.gov (United States)

    Digman, Matthew F; Shinners, Kevin J; Casler, Michael D; Dien, Bruce S; Hatfield, Ronald D; Jung, Hans-Joachim G; Muck, Richard E; Weimer, Paul J

    2010-07-01

    Switchgrass (Panicum virgatum L.) and reed canarygrass (Phalaris arundinacea L.) were pretreated under ambient temperature and pressure with sulfuric acid and calcium hydroxide in separate experiments. Chemical loadings from 0 to 100g (kg DM)(-1) and durations of anaerobic storage from 0 to 180days were investigated by way of a central composite design at two moisture contents (40% or 60% w.b.). Pretreated and untreated samples were fermented to ethanol by Saccharomyces cerevisiae D5A in the presence of a commercially available cellulase (Celluclast 1.5L) and beta-glucosidase (Novozyme 188). Xylose levels were also measured following fermentation because xylose is not metabolized by S. cerevisiae. After sulfuric acid pretreatment and anaerobic storage, conversion of cell wall glucose to ethanol for reed canarygrass ranged from 22% to 83% whereas switchgrass conversions ranged from 16% to 46%. Pretreatment duration had a positive effect on conversion but was mitigated with increased chemical loadings. Conversions after calcium hydroxide pretreatment and anaerobic storage ranged from 21% to 55% and 18% to 54% for reed canarygrass and switchgrass, respectively. The efficacy of lime pretreatment was found to be highly dependent on moisture content. Moreover, pretreatment duration was only found to be significant for reed canarygrass. Although significant levels of acetate and lactate were observed in the biomass after storage, S. cerevisiae was not found to be inhibited at a 10% solids loading. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  5. Mineral capacity of peat soils organic matter and entry of Cs137 into perennial grasses

    International Nuclear Information System (INIS)

    Tsybulko, N.N.; Shapsheeva, T.P.; Arastovich, T.V.; Zajtsev, A.A.

    2010-01-01

    The results of the study of peat soils organic substance structure with various peat ash content are given. Contents of active organic substance and carbon of microbial biomass in peat and boggy soil with 20% peat ash content is 3.0-3.5 and 1.6-1.8 times higher correspondingly, than thus in peaty-gley soil with 70% peat ash content. At peat and boggy soil with low peat ash content Cs137 transition into hay is minimal. 14 times higher than at peaty-gley soil with 70% peat ash content. Application of fertilizers at peat and boggy soil reduces Cs137 transition factor 4.7-6.4 times if compared to peaty-gley soil (2.1-4.7 times). Close positive interconnection between Cs137 transition factors from soil into the plants and organic carbon soil contents, absolute contents of potentially mineralized carbon and mineralization degree

  6. Developing Association Mapping in Polyploid Perennial Biofuel Grasses: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Buckler, Edward S; Casler, Michael D; Cherney, Jerome H

    2012-01-20

    This project had six objectives, four of which have been completed: 1) Association panels of diverse populations and linkage populations for switchgrass and reed canarygrass (~1,000 clones each) were assembled and planted in two sites (Ithaca, NY and Arlington, WI); 2) Key biofeedstock characteristics were evaluated in these panels for three field seasons; 3) High density SNP markers were developed in switchgrass; and 4) Switchgrass association panels and linkage populations were genotyped. The remaining two original objectives will be met in the next year, as the analyses are completed and papers published: 5) Switchgrass population structure and germplasm diversity will be evaluated; and 6) Association mapping will be established and marker based breeding values estimated in switchgrass. We also completed a study of the chromosome-number variation found in switchgrass.

  7. A Prairie Dog Abatement Program in San Juan County, Utah

    OpenAIRE

    Messmer, Terry A.; Keyes, Jim; McDonald, Roy

    1993-01-01

    Four species of prairie dogs are native to the plains and plateaus of the western United States. The most abundant and widely distributed of these is the blacktailed prairie dog, (Cynomys ludovicianus). This species has been a frequent topic of discussion at previous Great Plains Wildlife Damage Control workshops. Black-tailed prairie dog ecology and management was the topic of a panel discussion held at the Fifth Great Plains Wildlife Damage Control Workshop, in Lincoln, Nebraska (Timm and J...

  8. Cover Image Identification of Plant Species for Crop Pollinator Habitat Enhancement in the Northern Prairies

    Directory of Open Access Journals (Sweden)

    Diana Bizecki Robson

    2014-09-01

    Full Text Available Wild pollinators have a positive impact on the productivity of insect-pollinated crops. Consequently, landowners are being encouraged to maintain and grow wildflower patches to provide habitat for important pollinators. Research on plant-pollinator interaction matrices indicates that a small number of “core” plants provide a disproportionately high amount of pollen and nectar to insects. This matrix data can be used to help design wildflower plantings that provide optimal resources for desirable pollinators. Existing interaction matrices from three tall grass prairie preserves in the northern prairies were used to identify core plant species that are visited by wild pollinators of a common insect-pollinated crop, namely canola (Brassica napus L.. The wildflower preferences of each insect taxon were determined using quantitative insect visitation and floral abundance data. Phenology data were used to calculate the degree of floral synchrony between the wildflowers and canola. Using this information I ranked the 41 wildflowers that share insect visitors with canola according to how useful they are for providing pollinators with forage before and after canola flowers. The top five species were smooth blue aster (Symphyotrichum laeve (L. A. & D. Löve, stiff goldenrod (Solidago rigida L., wild bergamot (Monarda fistulosa L., purple prairie-clover (Dalea purpurea Vent. and Lindley’s aster (Symphyotrichum ciliolatum (Lindl. A. & D. Löve. By identifying the most important wild insects for crop pollination, and determining when there will be “pollen and nectar gaps”, appropriate plant species can be selected for companion plantings to increase pollinator populations and crop production.

  9. Perennial Pepperweed Patches - San Francisco Estuary [ds295

    Data.gov (United States)

    California Natural Resource Agency — This layer contains polygon data for the perennial pepperweed (Lepidium latifolium) database. This database represents distribution data collected within the areas...

  10. Genomics: a potential panacea for the perennial problem.

    Science.gov (United States)

    McClure, Kendra A; Sawler, Jason; Gardner, Kyle M; Money, Daniel; Myles, Sean

    2014-10-01

    Perennial crops represent important fresh and processed food sources worldwide, but advancements in breeding perennials are often impeded due to their very nature. The perennial crops we rely on most for food take several years to reach production maturity and require large spaces to grow, which make breeding new cultivars costly compared with most annual crops. Because breeding perennials is inefficient and expensive, they are often grown in monocultures consisting of small numbers of elite cultivars that are vegetatively propagated for decades or even centuries. This practice puts many perennial crops at risk for calamity since they remain stationary in the face of evolving pest and disease pressures. Although there is tremendous genetic diversity available to them, perennial crop breeders often struggle to generate commercially successful cultivars in a timely and cost-effective manner because of the high costs of breeding. Moreover, consumers often expect the same cultivars to be available indefinitely, and there is often little or no incentive for growers and retailers to take the risk of adopting new cultivars. While genomics studies linking DNA variants to commercially important traits have been performed in diverse perennial crops, the translation of these studies into accelerated breeding of improved cultivars has been limited. Here we explain the "perennial problem" in detail and demonstrate how modern genomics tools can significantly improve the cost effectiveness of breeding perennial crops and thereby prevent crucial food sources from succumbing to the perils of perpetual propagation. © 2014 Botanical Society of America, Inc.

  11. Prairies Water Management on Corps Lands

    Science.gov (United States)

    2009-02-01

    infiltration, autogenic mechanisms can lead to the recovery of essential soil processes. The Role of Organic Matter in Soil Formation. In a prairie...management in EP-1130-2-540 (USACE 2005), and does not have a fire management training program in place (USACE 2008). Some Corps resource managers...are trained and partner with other entities to conduct prescribed burns on Corps grasslands. However, prescribed burning as a management strategy is

  12. Radiative surface temperatures of the burned and unburned areas in a tallgrass prairie

    International Nuclear Information System (INIS)

    Asrar, G.; Harris, T.R.; Lapitan, R.L.; Cooper, D.I.

    1988-01-01

    This study was conducted in a natural tallgrass prairie area in the Flint Hills of Kansas. Our objective was to evaluate the surface radiative temperatures of burned and unburned treatments of the grassland as a means of delineating the areas covered by each treatment. Burning is used to remove the senescent vegetation resulting from the previous year's growth. Surface temperatures were obtained in situ and by an airborne scanner. Burned and unburned grass canopies had distinctly different diurnal surface radiative temperatures. Measurements of surface energy balance components revealed a difference in partitioning of the available energy between the two canopies, which resulted in the difference in their measured surface temperatures. The magnitude of this difference is dependent on the time of measurements and topographic conditions. (author)

  13. A feasibility study of perennial/annual plant species to restore soils contaminated with heavy metals

    Science.gov (United States)

    Zacarías, Montserrat; Beltrán, Margarita; Gilberto Torres, Luis; González, Abelardo

    A feasibility study was carried out to evaluate the application of perennial/annual plant species in a phytoextraction process of a previously washed industrial urban soil contaminated by nickel, arsenic and cupper. The plant species selected for this study were Ipomea (Ipomea variada); grass (Poa pratensis); grass mixture (Festuca rubra, Cynodon dactylon, Lolium multiforum, Pennisetum sp.); Monks Cress (Tropaeolum majus); ficus (Ficus benajamina) and fern (Pteris cretica). Soil was characterized and it presented the following heavy metals concentrations (dry weight): 80 mg of Ni/kg, 456-656 mg of As/kg and 1684-3166 mg of Cu/kg. Germination and survival in contaminated soil tests were conducted, from these, P. pratensis was discarded and the rest of plant species tested were used for the phytoextraction selection test. After 4 months of growth, biomass production was determined, and content of Ni, As and Cu was analyzed in plant’s tissue. Metal biological absorption coefficient (BAC), bio-concentration factor (BCF) and translocation factor (TF), were calculated. Regarding to biomass generation it was observed, in every case, an inhibition of the plant growth compared with blanks sown in a non contaminated soil; inhibition ranged from 22.5% for the Monk cress to 98% for Ipomea. Even though the later presented high BAC, BCF and TF, its growth was severely inhibited, and therefore, due its low biomass generation, it is not recommended for phytoextraction under conditions for this study. Heavy metals concentrations in plant’s tissue (dry weight) were as high as 866 mg Cu/kg and 602 mg As/kg for grass mixture; and 825 mg As/kg was observed for Monks cress. Grass mixture and monks cress had high BAC, BCF and TF, also they had high metal concentrations in its plants tissues and the lowest growth inhibition rates; hence the application in phytoextraction processes of these plants is advisable.

  14. Lesser prairie-chicken nest site selection, microclimate, and nest survival in association with vegetation response to a grassland restoration program

    Science.gov (United States)

    Boal, Clint W.; Grisham, Blake A.; Haukos, David A.; Zavaleta, Jennifer C.; Dixon, Charles

    2014-01-01

    captured at individual leks, and then for all leks pooled. There was no clear pattern of selection for treatment type for nest placement among hens associated with individual leks; however, when hens from all leks were pooled, we found nesting lesser prairie-chickens selected control plots for nesting over plots that were grazed, treated with tebuthiuron, or were both grazed and treated with tebuthiuron. Overall, the probability of a nest surviving the incubation period was 0.57 for this study and did not vary significantly among treatment types. In contrast to nesting preference for untreated habitats, lek use exhibited no noticeable selection of treatment type. Over the 10 years of the habitat management study, there was 91 percent less sand shinnery oak (Quercus havardii) in treated areas than untreated areas. The removal of sand shinnery oak made environmental soil moisture more available for grasses and forbs to germinate and grow. Grasses increased by 149 percent and forbs increased by 257 percent in treated areas as compared to untreated areas throughout the study period. Our combined results, including our habitat selection analysis at the individual lek level, indicated that reduced rates of herbicide and short-duration grazing treatments were not detrimental to nesting lesser prairie-chickens and that populations of lesser prairie-chickens in shrub-dominated ecosystems may benefit from reduced rates of herbicide application and short duration of grazing that results in increased habitat heterogeneity.

  15. The potential of C4 grasses for cellulosic biofuel production

    Directory of Open Access Journals (Sweden)

    Tim eWeijde

    2013-05-01

    Full Text Available With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulose feedstock for biofuel production is discussed. These include three important field crops - maize, sugarcane and sorghum - and two undomesticated perennial energy grasses - miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of

  16. Physiological Mechanism of Enhancing Salt Stress Tolerance of Perennial Ryegrass by 24-Epibrassinolide

    Directory of Open Access Journals (Sweden)

    Wenli Wu

    2017-06-01

    Full Text Available Brassinosteroids (BR regulate plant tolerance to salt stress but the mechanisms underlying are not fully understood. This study was to investigate physiological mechanisms of 24-epibrassinolide (EBR's impact on salt stress tolerance in perennial ryegrass (Lolium perenne L. The grass seedlings were treated with EBR at 0, 10, and 100 nM, and subjected to salt stress (250 mM NaCl. The grass irrigated with regular water without EBR served as the control. Salt stress increased leaf electrolyte leakage (EL, malondialdehyde (MDA, and reduced photosynthetic rate (Pn. Exogenous EBR reduced EL and MDA, increased Pn, chlorophyll content, and stomatal conductance (gs. The EBR applications also alleviated decline of superoxide dismutase (SOD and catalase (CAT and ascorbate peroxidase (APX activity when compared to salt treatment alone. Salt stress increased leaf abscisic acid (ABA and gibberellin A4 (GA4 content but reduced indole-3-acetic acid (IAA, zeatin riboside (ZR, isopentenyl adenosine (iPA, and salicylic acid (SA. Exogenous EBR at 10 nm and 100 nM increased ABA, and iPA content under salt stress. The EBR treatment at 100 nM also increased leaf IAA, ZR, JA, and SA. In addition, EBR treatments increased leaf proline and ions (K+, Mg2+, and Ca2+ content, and reduced Na+/K+ in leaf tissues. The results of this study suggest that EBR treatment may improve salt stress tolerance by increasing the level of selected hormones and antioxidant enzyme (SOD and CAT activity, promoting accumulation of proline and ions (K+, Ca2+, and Mg2+ in perennial ryegrass.

  17. Preserving prairies: Understanding temporal and spatial patterns of invasive annual bromes in the Northern Great Plains

    Science.gov (United States)

    Ashton, Isabel; Symstad, Amy J.; Davis, Christopher; Swanson, Daniel J.

    2016-01-01

    Two Eurasian invasive annual brome grasses, cheatgrass (Bromus tectorum) and Japanese brome (Bromus japonicus), are well known for their impact in steppe ecosystems of the western United States where these grasses have altered fire regimes, reduced native plant diversity and abundance, and degraded wildlife habitat. Annual bromes are also abundant in the grasslands of the Northern Great Plains (NGP), but their impact and ecology are not as well studied. It is unclear whether the lessons learned from the steppe will translate to the mixed-grass prairie where native plant species are adapted to frequent fires and grazing. Developing a successful annual brome management strategy for National Park Service units and other NGP grasslands requires better understanding of (1) the impact of annual bromes on grassland condition; (2) the dynamics of these species through space and time; and (3) the relative importance of environmental factors within and outside managers' control for these spatiotemporal dynamics. Here, we use vegetation monitoring data collected from 1998 to 2015 in 295 sites to relate spatiotemporal variability of annual brome grasses to grassland composition, weather, physical environmental characteristics, and ecological processes (grazing and fire). Concern about the impact of these species in NGP grasslands is warranted, as we found a decline in native species richness with increasing annual brome cover. Annual brome cover generally increased over the time of monitoring but also displayed a 3- to 5-yr cycle of reduction and resurgence. Relative cover of annual bromes in the monitored areas was best predicted by park unit, weather, extant plant community, slope grade, soil composition, and fire history. We found no evidence that grazing reduced annual brome cover, but this may be due to the relatively low grazing pressure in our study. By understanding the consequences and patterns of annual brome invasion, we will be better able to preserve and restore

  18. Chicago's Columbus Park: The Prairie Idealized. Teaching with Historic Places.

    Science.gov (United States)

    Bachrach, Julia Sniderman; Nathan, Jo Ann

    Twenty-four year old Jens Jensen came to the United States, settled in Chicago (Illinois), and promptly fell in love with the Midwest's prairie landscape. Although some thought that prairie was boring, monotonous, and ordinary, Jensen saw great beauty in the tree-filled groves, long winding rivers, natural rock formations and waterfalls, and the…

  19. Growth and nutritional evaluation of napier grass hybrids as forage for ruminants

    Directory of Open Access Journals (Sweden)

    Brian Turano

    2016-09-01

    Full Text Available Napier grass is a perennial, tropical C-4 grass that can produce large amounts of forage. However, low temperatures and drought stress limit its productivity and nutritive value as a forage. To overcome these limitations, pearl millet × napier grass hybrids (PMN were developed. It was hypothesized that PMN hybrids were more drought-tolerant, produced higher yields, and had higher nutritive value than napier grass varieties. The yield and nutritive value of 4 napier grass varieties (Bana grass, Mott, MB4 and N51 and 4 PMN hybrids (PMN2, PMN3, 5344 and 4604 were determined with or without irrigation in a strip plot design in Hawaii. Hybrid PMN3 outperformed napier grass varieties and the other hybrids for yield, while 5344 showed higher nutritional content and digestibility than most other grasses. Dry matter yields during the 110-day study period ranged from 10.3 to 32.1 t/ha without irrigation and 19.6 to 55.8 t/ha with irrigation, indicating that moisture stress was limiting performance in raingrown pastures. Only hybrids PMN3 and PMN2 and variety MB4 showed significant growth responses to irrigation. Further work is needed to evaluate the hybrids in a range of environments over much longer periods to determine if these preliminary results can be reproduced over the long term. Similarly, feeding studies with animals are needed to determine if the in vitro data for digestibility are reflected in superior performance for the promising hybrids.Keywords: Biomass, cattle, in vitro digestion, nutrient content, Pennisetum, tropical grasses.DOI: 10.17138/TGFT(4168-178

  20. Agroecology of Novel Annual and Perennial Crops for Biomass Production

    DEFF Research Database (Denmark)

    Manevski, Kiril; Jørgensen, Uffe; Lærke, Poul Erik

    The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production.......The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production....

  1. Determination of microbial protein in perennial ryegrass silage

    NARCIS (Netherlands)

    Driehuis, F.; Wikselaar, van P.G.

    2001-01-01

    The microbial matter fraction was determined in perennial ryegrass silages of different dry-matter (DM) contents, ensiled with or without Lactobacillus plantarum. 15N-Leucine and the bacterial cell wall constituent diaminopimelic acid (DAPA) were used as markers for microbial-N. Perennial ryegrass

  2. Transfer of radiocaesium to barley, rye grass and pea

    International Nuclear Information System (INIS)

    Oehlenschlaeger, M.; Gissel-Nielsen, G.

    1989-11-01

    In areas with intensive farming, as in Denmark, it is of great interest to identify possible countermeasures to be taken in order to reduce the longterm effects of radioactive contamination of arable land. The most important longer-lived radionuclides from the Chernobyl were 137 Cs and 134 Cs. The aim of the present project was to identify crops with relatively low or high root uptake of these two isotopes. Although such differences may be small, a shift in varieties might be a cost-effective way to reduce collective doses. The experiment was carried out at Risoe National Laboratory in the summer of 1988. The species used were: spring barley (Hordeum vulgare L) varieties: Golf, Apex, Anker, Sila; Perennial rye grass (Lolium perenne L.) varieties: Darbo (early) and Patoro (late); Italian rye-grass (Lolium multiflorum) variety: Prego; and pea (Pisum arvense L.) variety: Bodil. Each crop was grown in two types of soil, a clay-loam and an organic soil. 137 Cs was added to the clay-loam. The organic soil, which was contaminated with 137 Cs from the Chernobyl accident, was supplied with 134 Cs. Sila barley and Italian rye-grass were identified among the species tested as plants with a relative high uptake of radio-caesium. (author)

  3. 78 FR 17224 - Environmental Impact Statement; Proposed South Puget Sound Prairie Habitat Conservation Plan...

    Science.gov (United States)

    2013-03-20

    ... sizable portion of South Puget Sound Prairie habitat is located in the urban-rural interface and in the...-FF01E00000] Environmental Impact Statement; Proposed South Puget Sound Prairie Habitat Conservation Plan... permit application would be associated the South Puget Sound Prairie Habitat Conservation Plan (Prairie...

  4. Restoration and winter avian use of isolated prairies in eastern Texas

    Science.gov (United States)

    D. Craig Rudolph; Dave E. Plair; Dan Jones; J. Howard Williamson; Clifford E. Shackelford; Richard R. Schaefer; Joshua B. Pierce

    2014-01-01

    Numerous isolated prairies exist, or existed, on the West Gulf Coastal Plain east of the main distribution of the prairie ecosystem. Changing land-use patterns and suppression of wildfire have destroyed almost all of these small prairie occurrences. Intensified restoration and management of degraded prairie habitat on the Sam Houston National Forest in southeastern...

  5. Spatially explicit modeling of lesser prairie-chicken lek density in Texas

    Science.gov (United States)

    Timmer, Jennifer M.; Butler, M.J.; Ballard, Warren; Boal, Clint W.; Whitlaw, Heather A.

    2014-01-01

    As with many other grassland birds, lesser prairie-chickens (Tympanuchus pallidicinctus) have experienced population declines in the Southern Great Plains. Currently they are proposed for federal protection under the Endangered Species Act. In addition to a history of land-uses that have resulted in habitat loss, lesser prairie-chickens now face a new potential disturbance from energy development. We estimated lek density in the occupied lesser prairie-chicken range of Texas, USA, and modeled anthropogenic and vegetative landscape features associated with lek density. We used an aerial line-transect survey method to count lesser prairie-chicken leks in spring 2010 and 2011 and surveyed 208 randomly selected 51.84-km(2) blocks. We divided each survey block into 12.96-km(2) quadrats and summarized landscape variables within each quadrat. We then used hierarchical distance-sampling models to examine the relationship between lek density and anthropogenic and vegetative landscape features and predict how lek density may change in response to changes on the landscape, such as an increase in energy development. Our best models indicated lek density was related to percent grassland, region (i.e., the northeast or southwest region of the Texas Panhandle), total percentage of grassland and shrubland, paved road density, and active oil and gas well density. Predicted lek density peaked at 0.39leks/12.96km(2) (SE=0.09) and 2.05leks/12.96km(2) (SE=0.56) in the northeast and southwest region of the Texas Panhandle, respectively, which corresponds to approximately 88% and 44% grassland in the northeast and southwest region. Lek density increased with an increase in total percentage of grassland and shrubland and was greatest in areas with lower densities of paved roads and lower densities of active oil and gas wells. We used the 2 most competitive models to predict lek abundance and estimated 236 leks (CV=0.138, 95% CI=177-306leks) for our sampling area. Our results suggest that

  6. The use of less common grass varieties as a factor of increasing forage lands productivity

    Directory of Open Access Journals (Sweden)

    В. Д. Бугайов

    2017-03-01

    Full Text Available Purpose. To assess introduced samples of drought-resistant species of perennial grasses, select a promising parent material and create on its base high-yielding varie­ ies with economic characters. Methods. Field experiment, laboratory testing. Results. The results of studies on introduction and breeding were given aimed to improve drought tolerance of non-traditional perennial grasses under the conditions of the Right-Bank Forest-Steppe zone of Ukraine. Based on the selected parent material, varieties were created by the use of hybridization and ecotype breeding methods and then entered into the State Register of plant varieties suitable for dissemination in Ukraine, among them: intermediate wheatgrass (Elytrigia intermedia (Host Nevski – ‘Hors’, crested wheatgrass (Agropyron cristatum (L. Gaertn. – ‘Petrivskyi’; meadow brome (Bromus riparia Rehm. – ‘Boian’; slender wheatgrass (Roegneria trachycaulon (Link Nevski – ‘Co­umb’. As compared with conventional, relatively drought-tolerant species of smooth brome (Bromopsis inermis (Leyss. Holub – ‘Mars’, increment of dry matter content of these species in the extreme drought conditions of 2011 was increased by 1,52–3,73 t/ha. Under more sufficient moistening conditions of 2012, slender wheatgrass ‘Columb’ was at the level of the сheck variety in terms of this indicator. Other varieties exceeded it by 1.44–3.22 t/ha. The data was given including seed productivity and sowing quality indicators, after-ripening duration and economic fitness of seeds. Conclusions. The use of the recommended varieties of drought-resistant species of perennial grasses as part of grass mixtures will increase significantly the productivity of grasslands and pastures in the current context of climate change.

  7. Environmental Impacts of Wind Power Development on the Population Biology of Greater Prairie-Chickens

    Energy Technology Data Exchange (ETDEWEB)

    Sandercock, Brett K. [Kansas State University

    2013-05-22

    power development appears to affect movements in breeding habitats but not nest site selection of female prairie chickens during the breeding season. 5. We tested the effects of wind power development on five components of female fecundity: timing of clutch initiation, clutch size of first nests and renests, nest survival, and hatchability of eggs. Average date of clutch initiation was 26 April, clutch size was 12.7 and 10.6 eggs for first nests and renests, probability of nest survival was low at 0.18, but egg hatchability was high at 0.79. Wind power development had no impact on reproductive effort or nesting success, and all five components of fecundity were not related to treatment period or distance to turbine. Nest survival was the main factor limiting reproductive output of female prairie chickens and most losses were due to predation. Daily nest survival was strongly related to vegetative cover at the nest. Changes to rangeland management practices that would double nesting cover from 2.5 to 5 dm would triple the probability of nest survival from 0.17 to 0.52. Grass and forb cover had weak positive effects on daily nest survival whereas shrub cover, proximity to woodlands, and recent rainfall had negative effects. Reproductive performance of prairie chickens is low in managed rangelands in northcentral Kansas and efforts to improve range conditions and reduce predator activity would aid recovery of prairie chicken populations. 6. We used molecular methods to investigate patterns of natal dispersal in prairie chickens. High rates of nest failure limited the number of young that we could sample. Direct detections of natal dispersal were limited because survival of newly hatched chicks to become adults were low and because we were unable to detect dispersal distances outside of our study area. Direct observations of natal movements were limited and were inadequate to make conclusions about the potential impacts of wind energy development on natal dispersal. Spatial

  8. Oxytocin reduces alcohol consumption in prairie voles.

    Science.gov (United States)

    Stevenson, J R; Wenner, S M; Freestone, D M; Romaine, C C; Parian, M C; Christian, S M; Bohidar, A E; Ndem, J R; Vogel, I R; O'Kane, C M

    2017-10-01

    Alcohol use disorder (AUD) negatively affects millions of people every year in the United States, and effective treatments for AUD are still needed. The neuropeptide oxytocin has shown promise for reducing alcohol drinking in mice and rats. Because oxytocin also plays a key role in complex prosocial behaviors like bonding and attachment, we tested the effect of oxytocin on alcohol drinking in prairie voles, a species that both consumes high amounts of alcohol and forms oxytocin dependent social bonds in a manner similar to humans. Oxytocin treatment (1.0, 3.0, and 10.0mg/kg, i.p.) reduced alcohol consumption in male and female prairie voles in animals that had access to 15% ethanol vs water every other day for 12 alcohol drinking sessions. In animals with continuous access to 15% alcohol and water, oxytocin (3.0mg/kg) reduced alcohol consumption only in the first hour of access after treatment, with no significant effects on consumption over the 24-hr period. In an open field locomotor test, oxytocin (1.0, 3.0, and 10.0mg/kg, i.p.) did not affect overall locomotor activity; however, ethanol (2g/kg, i.p.) increased locomotor activity in males and females, and produced anxiolytic effects (increased time in the center of an open field) in females only. Because prairie voles have been shown to match the alcohol consumption of their cage mate, we evaluated the relationship between cage mates' alcohol drinking. There was an overall pattern of social facilitation (consumption by one cage mate predicted consumption by the other cage mate); however, we found significant individual differences across cages in which many cages did not show significant matching, and, in some cases one cage mate's consumption negatively predicted the other cage mate's consumption. Overall, our data provide support for the potential of oxytocin as a treatment to reduce alcohol consumption. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. PHYTOREMEDIATION OF PESTICIDE MIXTURES WITH NATIVE PRAIRIE GRASSES. (R825549C045)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  10. Soil Aggregate Stability and Grassland Productivity Associations in a Northern Mixed-Grass Prairie.

    Directory of Open Access Journals (Sweden)

    Kurt O Reinhart

    Full Text Available Soil aggregate stability data are often predicted to be positively associated with measures of plant productivity, rangeland health, and ecosystem functioning. Here we revisit the hypothesis that soil aggregate stability is positively associated with plant productivity. We measured local (plot-to-plot variation in grassland community composition, plant (aboveground biomass, root biomass, % water-stable soil aggregates, and topography. After accounting for spatial autocorrelation, we observed a negative association between % water-stable soil aggregates (0.25-1 and 1-2 mm size classes of macroaggregates and dominant graminoid biomass, and negative associations between the % water-stable aggregates and the root biomass of a dominant sedge (Carex filifolia. However, variation in total root biomass (0-10 or 0-30 cm depths was either negatively or not appreciably associated with soil aggregate stabilities. Overall, regression slope coefficients were consistently negative thereby indicating the general absence of a positive association between measures of plant productivity and soil aggregate stability for the study area. The predicted positive association between factors was likely confounded by variation in plant species composition. Specifically, sampling spanned a local gradient in plant community composition which was likely driven by niche partitioning along a subtle gradient in elevation. Our results suggest an apparent trade-off between some measures of plant biomass production and soil aggregate stability, both known to affect the land's capacity to resist erosion. These findings further highlight the uncertainty of plant biomass-soil stability associations.

  11. Contrasting nest survival patterns for ducks and songbirds in northern mixed-grass prairie

    Science.gov (United States)

    Grant, Todd; Shaffer, Terry L.; Madden, Elizabeth M.; Nenneman, Melvin P.

    2017-01-01

    Management actions intended to protect or improve habitat for ducks may benefit grassland-nesting passerines, but scant information is available to explore this assumption. During 1998–2003, we examined nest survival of ducks and songbirds to determine whether effects of prescribed fire and other habitat features (e.g., shrub cover and distance to habitat edges) were similar for ducks and passerines breeding in North Dakota. We used the logistic-exposure method to estimate survival of duck and songbird nests (n = 3,171). We used an information-theoretic approach to identify factors that most influenced nest survival. Patterns of nest survival were markedly different between taxonomic groups. For ducks, nest survival was greater during the first postfire nesting season (daily survival rate [DSR] = 0.957, 85% CI = 0.951–0.963), relative to later postfire nesting seasons (DSR = 0.946, 85% CI = 0.942–0.950). Furthermore duck nest survival and nest densities were inversely related. Duck nest survival also was greater as shrub cover decreased and as distance from cropland and wetland edges increased. Passerines had lower nest survival during the first postfire nesting season (DSR = 0.934, 85% CI = 0.924–0.944), when densities also were low compared to subsequent postfire nesting seasons (DSR = 0.947, 85% CI = 0.944–0.950). Parasitism by brown-headed cowbirds (Molothrus ater) reduced passerine nest survival and this effect was more pronounced during the first postfire nesting season compared to subsequent nesting seasons. Passerine nest survival was greater as shrub cover decreased and perhaps for more concealed nests. Duck and songbird nest survival rates were not correlated during this study and for associated studies that examined additional variables using the same dataset, suggesting that different mechanisms influenced their survival. Based on our results, ducks should not be considered direct surrogates for passerines when predicting effects of prescribed fire, shrub cover, and habitat edges on nest survival.

  12. CANOPY ARCHITECTURE, LIGHT EXTINCTION AND SELF-SHADING OF A PRAIRIE GRASS, ANDROPOGON GERARDII. (R825796)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. Meadow-grass gall midge

    DEFF Research Database (Denmark)

    Hansen, Lars Monrad

    The area with meadow-grass (Poa pratensis, L.) grown for seed production in Den-mark is a significant proportion of the entire seed production. The meadow-grass gall midge (Mayetiola schoberi, Barnes 1958) is of considerable economic importance since powerful attacks can reduce the yield...

  14. Integrated production of warm season grasses and agroforestry for biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Samson, R.; Omielan, J. [Resource Efficient Agricultural Production-Canada, Ste, Anne de Bellevue, Quebec (Canada); Girouard, P.; Henning, J. [McGill Univ., Ste. Anne de Bellevue, Quebec (Canada)

    1993-12-31

    Increased research on C{sub 3} and C{sub 4} perennial biomass crops is generating a significant amount of information on the potential of these crops to produce large quantities of low cost biomass. In many parts of North America it appears that both C{sub 3} and C{sub 4} species are limited by water availability particularly on marginal soils. In much of North America, rainfall is exceeded by evaporation. High transpiration rates by fast growing trees and rainfall interception by the canopy appear to indicate that this can further exacerbate the problem of water availability. C{sub 4} perennial grasses appear to have distinct advantages over C{sub 3} species planted in monoculture systems particularly on marginal soils. C{sub 4} grasses historically predominated over much of the land that is now available for biomass production because of their adaptation to low humidity environments and periods of low soil moisture. The planting of short rotation forestry (SRF) species in an energy agroforestry system is proposed as an alternative production strategy which could potentially alleviate many of the problems associated with SRF monocultures. Energy agroforestry would be complementary to both production of conventional farm crops and C{sub 4} perennial biomass crops because of beneficial microclimatic effects.

  15. Nutrient addition shifts plant community composition towards earlier flowering species in some prairie ecoregions in the U.S. Central Plains.

    Directory of Open Access Journals (Sweden)

    Lori Biederman

    Full Text Available The distribution of flowering across the growing season is governed by each species' evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie across the U.S. Central Plains to determine how nutrient (nitrogen (N, phosphorus, and potassium (+micronutrient addition alters the temporal patterns of plant flowering traits. We calculated total community flowering potential (FP by distributing peak-season plant cover values across the growing season, allocating each species' cover to only those months in which it typically flowers. We also generated separate FP profiles for exotic and native species and functional group. We compared the ability of the added nutrients to shift the distribution of these FP profiles (total and sub-groups across the growing season. In all ecoregions, N increased the relative cover of both exotic species and C3 graminoids that flower in May through August. The cover of C4 graminoids decreased with added N, but the response varied by ecoregion and month. However, these functional changes only aggregated to shift the entire community's FP profile in the tall-grass prairie, where the relative cover of plants expected to flower in May and June increased and those that flower in September and October decreased with added N. The relatively low native cover in May and June may leave this ecoregion vulnerable to disturbance-induced invasion by exotic species that occupy this temporal niche. There was no change in the FP profile of the mixed and short-grass prairies with N addition as increased abundance of exotic species and C3 graminoids replaced other species that flower at the same time. In these communities a disturbance other than nutrient addition may be required to disrupt phenological

  16. Drought, Climate Change and the Canadian Prairies

    Science.gov (United States)

    Stewart, R. E.

    2010-03-01

    The occurrence of drought is a ubiquitous feature of the global water cycle. Such an extreme does not necessarily lead to an overall change in the magnitude of the global water cycle but it of course affects the regional cycling of water. Droughts are recurring aspects of weather and climate extremes as are floods and tornadoes, but they differ substantially since they have long durations and lack easily identified onsets and terminations. Drought is a relatively common feature of the North American and Canadian climate system and all regions of the continent are affected from time-to-time. However, it tends to be most common and severe over the central regions of the continent. The Canadian Prairies are therefore prone to drought. Droughts in the Canadian Prairies are distinctive in North America. The large scale atmospheric circulations are influenced by blocking from intense orography to the west and long distances from all warm ocean-derived atmospheric water sources; growing season precipitation is generated by a highly complex combination of frontal and convective systems; seasonality is severe and characterized by a relatively long snow-covered and short growing seasons; local surface runoff is primarily produced by snowmelt water; there is substantial water storage potential in the poorly drained, post-glacial topography; and aquifers are overlain by impermeable glacial till, but there are also important permeable aquifers. One example of Prairie drought is the recent one that began in 1999 with cessation of its atmospheric component in 2004/2005 and many of its hydrological components in 2005. This event produced the worst drought for at least a hundred years in parts of the Canadian Prairies. Even in the dust bowl of the 1930s, no single year over the central Prairies were drier than in 2001. The drought affected agriculture, recreation, tourism, health, hydro-electricity, and forestry in the Prairies. Gross Domestic Product fell some 5.8 billion and

  17. Analysis of DNA methylation of perennial ryegrass under drought using the methylation-sensitive amplification polymorphism (MSAP) technique.

    Science.gov (United States)

    Tang, Xiao-Mei; Tao, Xiang; Wang, Yan; Ma, Dong-Wei; Li, Dan; Yang, Hong; Ma, Xin-Rong

    2014-12-01

    Perennial ryegrass (Lolium perenne), an excellent grass for forage and turf, is widespread in temperate regions. Drought is an important factor that limits its growth, distribution, and yield. DNA methylation affects gene expression and plays an important role in adaptation to adverse environments. In this study, the DNA methylation changes in perennial ryegrass under drought stress were assessed using methylation-sensitive amplified polymorphism (MSAP). After 15 days of drought stress treatment, the plant height was less than half of the control, and the leaves were smaller and darker. Genome-wide, a total of 652 CCGG sites were detected by MSAP. The total methylation level was 57.67 and 47.39 % in the control and drought treatment, respectively, indicating a decrease of 10.28 % due to drought exposure. Fifteen differentially displayed DNA fragments in MSAP profiles were cloned for sequencing analysis. The results showed that most of the genes involved in stress responses. The relative expression levels revealed that three demethylated fragments were up-regulated. The expression of a predicted retrotransposon increased significantly, changing from hypermethylation to non-methylation. Although the extent of methylation in two other genes decreased, the sites of methylation remained, and the expression increased only slightly. All of these results suggested that drought stress decreased the total DNA methylation level in perennial ryegrass and demethylation up-regulated related gene expressions and that the extent of methylation was negatively correlated with expression. Overall, the induced epigenetic changes in genome probably are an important regulatory mechanism for acclimating perennial ryegrass to drought and possibly other environmental stresses.

  18. Ecosystem-service tradeoffs associated with switching from annual to perennial energy crops in riparian zones of the US Midwest.

    Directory of Open Access Journals (Sweden)

    Timothy D Meehan

    Full Text Available Integration of energy crops into agricultural landscapes could promote sustainability if they are placed in ways that foster multiple ecosystem services and mitigate ecosystem disservices from existing crops. We conducted a modeling study to investigate how replacing annual energy crops with perennial energy crops along Wisconsin waterways could affect a variety of provisioning and regulating ecosystem services. We found that a switch from continuous corn production to perennial-grass production decreased annual income provisioning by 75%, although it increased annual energy provisioning by 33%, decreased annual phosphorous loading to surface water by 29%, increased below-ground carbon sequestration by 30%, decreased annual nitrous oxide emissions by 84%, increased an index of pollinator abundance by an average of 11%, and increased an index of biocontrol potential by an average of 6%. We expressed the tradeoffs between income provisioning and other ecosystem services as benefit-cost ratios. Benefit-cost ratios averaged 12.06 GJ of additional net energy, 0.84 kg of avoided phosphorus pollution, 18.97 Mg of sequestered carbon, and 1.99 kg of avoided nitrous oxide emissions for every $1,000 reduction in income. These ratios varied spatially, from 2- to 70-fold depending on the ecosystem service. Benefit-cost ratios for different ecosystem services were generally correlated within watersheds, suggesting the presence of hotspots--watersheds where increases in multiple ecosystem services would come at lower-than-average opportunity costs. When assessing the monetary value of ecosystem services relative to existing conservation programs and environmental markets, the overall value of enhanced services associated with adoption of perennial energy crops was far lower than the opportunity cost. However, when we monitized services using estimates for the social costs of pollution, the value of enhanced services far exceeded the opportunity cost. This

  19. Southern marl prairies conceptual ecological model

    Science.gov (United States)

    Davis, S.M.; Loftus, W.F.; Gaiser, E.E.; Huffman, A.E.

    2005-01-01

    About 190,000 ha of higher-elevation marl prairies flank either side of Shark River Slough in the southern Everglades. Water levels typically drop below the ground surface each year in this landscape. Consequently, peat soil accretion is inhibited, and substrates consist either of calcitic marl produced by algal periphyton mats or exposed limestone bedrock. The southern marl prairies support complex mosaics of wet prairie, sawgrass sawgrass (Cladium jamaicense), tree islands, and tropical hammock communities and a high diversity of plant species. However, relatively short hydroperiods and annual dry downs provide stressful conditions for aquatic fauna, affecting survival in the dry season when surface water is absent. Here, we present a conceptual ecological model developed for this landscape through scientific concensus, use of empirical data, and modeling. The two major societal drivers affecting the southern marl prairies are water management practices and agricultural and urban development. These drivers lead to five groups of ecosystem stressors: loss of spatial extent and connectivity, shortened hydroperiod and increased drought severity, extended hydroperiod and drying pattern reversals, introduction and spread of non-native trees, and introduction and spread of non-native fishes. Major ecological attributes include periphyton mats, plant species diversity and community mosaic, Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), marsh fishes and associated aquatic fauna prey base, American alligator (Alligator mississippiensis), and wading bird early dry season foraging. Water management and development are hypothesized to have a negative effect on the ecological attributes of the southern marl prairies in the following ways. Periphyton mats have decreased in cover in areas where hydroperiod has been significantly reduced and changed in community composition due to inverse responses to increased nutrient availability. Plant species diversity and

  20. Sylvatic plague vaccine and management of prairie dogs

    Science.gov (United States)

    Rocke, Tonie E.

    2012-01-01

    Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at the University of Wisconsin (UW), have developed a sylvatic plague vaccine that shows great promise in protecting prairie dogs against plague (Mencher and others, 2004; Rocke and others, 2010). Four species of prairie dogs reside in the United States and Canada, and all are highly susceptible to plague and regularly experience outbreaks with devastating losses. Along with habitat loss and poisoning, plague has contributed to a significant historical decline in prairie dog populations. By some estimates, prairie dogs now occupy only 1 to 2 percent of their former range (Proctor and others, 2006), with prairie dog colonies being now much smaller and fragmented than they were historically, making individual colonies more vulnerable to elimination by plague (Antolin and others, 2002). At least one species, the Utah prairie dog (Cynomys parvidens) is listed by the U.S. Fish and Wildlife Service (FWS) as "threatened." Controlling plague is a vital concern for ongoing management and conservation efforts for prairie dogs. Current efforts to halt the spread of plague in prairie dog colonies typically rely on dusting individual prairie dog burrows with pesticides to kill plague-infected fleas. Although flea-control insecticides, such as deltamethrin, are useful in stopping plague outbreaks in these prairie dog colonies, dusting of burrows is labor intensive and time consuming and may affect other insects and arthropods. As an alternative approach, NWHC and UW scientists developed a sylvatic plague vaccine (SPV) for prairie dogs that can be delivered via oral bait. Laboratory studies have shown that consumption of this vaccine-laden bait by different prairie dog species results in significant protection against plague infection that can last for at least 9 months (Rocke and others, 2010; Rocke, unpublished). Work has now shifted to optimizing baits and distribution methods for

  1. Extending juvenility in grasses

    Energy Technology Data Exchange (ETDEWEB)

    Kaeppler, Shawn; de Leon Gatti, Natalia; Foerster, Jillian

    2017-04-11

    The present invention relates to compositions and methods for modulating the juvenile to adult developmental growth transition in plants, such as grasses (e.g. maize). In particular, the invention provides methods for enhancing agronomic properties in plants by modulating expression of GRMZM2G362718, GRMZM2G096016, or homologs thereof. Modulation of expression of one or more additional genes which affect juvenile to adult developmental growth transition such as Glossy15 or Cg1, in conjunction with such modulation of expression is also contemplated. Nucleic acid constructs for down-regulation of GRMZM2G362718 and/or GRMZM2G096016 are also contemplated, as are transgenic plants and products produced there from, that demonstrate altered, such as extended juvenile growth, and display associated phenotypes such as enhanced yield, improved digestibility, and increased disease resistance. Plants described herein may be used, for example, as improved forage or feed crops or in biofuel production.

  2. Recycling of uranium by a perennial vegetation

    International Nuclear Information System (INIS)

    Thiry, Y.

    2005-01-01

    At sites of large scale mining and processing of uranium ore, tailings and waste rock piles are today the most visible relics of the uranium extractive industry. These mining relics are constantly subjected to weathering and leaching processes causing the dissemination of radioactive and toxic elements and sometimes requiring remedial operations. The in situ remediation of waste rock piles usually includes their revegetation for minimizing the water infiltration and for increasing surface soil stability. Thanks to its biomass density and longevity, the perennial vegetation plays an important role in stabilisation of the water cycling. The buffer role of forest vegetation can reduce water export from watersheds as well as erosion and hydrological losses of chemicals including radionuclides from contaminated sites. If long term reduction of contaminant dispersion at revegetated uranium mining sites is to be fully appreciated, then the extent of radioactive contaminant availability to forest vegetation and ecosystem cycling as well as the possible economic valorisation of the woody products must be considered. Concerned study focused on a Scots pine plantation established 35 years ago on a uranium waste rock pile (Wismuth GmbH) situated near Schlema (Germany). This investigation aimed at quantifying the mobility of uranium in the mining debris and its transport to the different tree compartments with emphasis on the processes involved. The influence of pine vegetation on uranium cycling dynamics was further assessed in terms of annual fluxes)

  3. Effects of species diversity on seasonal variation in herbage yield and nutritive value of seven binary grass-legume mixtures and pure grass under cutting

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2016-01-01

    Intensively managed sown temperate grasslands are generally of low species diversity, although swards based on grass-legume mixtures may have superior productivity and herbage quality than grass-only swards. We conducted a cutting experiment over two years to test the effect of species composition...... and diversity on herbage yield, contents of N, neutral detergent fibre (NDF) and in vitro organic matter digestibility (IVOMD). Perennial ryegrass (PR, Lolium perenne) was sown alone and with each of four forage legumes: red clover (RC, Trifolium pratense), lucerne (LU, Medicago sativa), birdsfoot trefoil (BT......, Lotus corniculatus) and white clover (WC, Trifolium repens); WC was also sown with hybrid ryegrass (HR, Lolium × boucheanum), meadow fescue (MF, Festuca pratensis) and timothy (TI, Phleum pratense). Herbage productivity was lowest in pure PR followed by PR/BT, and highest in PR/RC; this mixture had...

  4. Allium hookeri , Thw. Enum. A lesser known terrestrial perennial ...

    African Journals Online (AJOL)

    A lesser known terrestrial perennial herb used as food and its ethnobotanical ... from the wilderness, for consumption and traditional healing of various ailments. ... plants, the lifestyles of the people are changed and they prefer 'junk foods'.

  5. The Forecasting of Adaptation Potential of Herbaceous Perennials

    Directory of Open Access Journals (Sweden)

    Belykh, O. A.

    2013-04-01

    Full Text Available This work investigates the problem of the ecobiomorph productive features formation of perennial herbs Ranunculaceae family forecasting on the basis of quantitative connections of species parameters with the leading geomorphological factors of South Siberia environment.

  6. Ecology and management of the Prairie Division

    Science.gov (United States)

    Roger C. Anderson

    2012-01-01

    Grasslands occurred on all continents, comprised almost 42 percent of the world’s plant cover, and once covered approximately 46 million km2 of the Earth’s surface. Grasslands contain few trees or shrubs, are dominated by grasses (members of the family Poaceae), and have a mixture of nongraminoid herbaceous species called forbs. Plant families...

  7. Bacterial endophytes of perennial crops for management of plant disease

    OpenAIRE

    Melnick, Rachel L.; Bailey, B.A.; Backman, Paul A.

    2013-01-01

    Metadata only record Bacterial endophytes, microorganisms which inhabit the internal tissues of plants, can suppress disease and are often used as a biological control in annual crops. Less research, however, has been applied to the use of bacterial endophytes to prevent disease in perennial crops, which presents a more complex challenge. However, exploration of their potential as a biological control in perennial crops has been limited. This chapter assembles current knowledge on the subj...

  8. Immunochemical Analysis of Paxilline and Ergot Alkaloid Mycotoxins in Grass Seeds and Plants.

    Science.gov (United States)

    Bauer, Julia I; Gross, Madeleine; Cramer, Benedikt; Humpf, Hans-Ulrich; Hamscher, Gerd; Usleber, Ewald

    2018-01-10

    Limited availability of toxin standards for lolitrem B and ergovaline impedes routine control of grasses for endophyte toxins. This study aimed at assessing the applicability of an enzyme immunoassay (EIA) for the indole-diterpene mycotoxin paxilline, in combination with a generic EIA for ergot alkaloids, as alternative parameters for screening purposes. Analysis of grass seeds and model pastures of four different grass species showed that both EIAs yielded highly positive results for paxilline and ergot alkaloids in perennial ryegrass seeds. Furthermore, evidence for natural occurrence of paxilline in grass in Germany was obtained. High performance liquid chromatography-tandem mass spectrometry analysis qualitatively confirmed the paxilline EIA results but showed that paxilline analogues 1'-O-acetylpaxilline and 13-desoxypaxilline were the predominant compounds in seeds and grass. In the absence of easily accessible reference standards for specific analysis of some major endophyte toxins, analysis of paxilline and ergot alkaloids by EIA may be suitable substitute parameters. The major advantage of this approach is its ease of use and speed, providing an analytical tool which could enhance routine screening for endophyte toxins in pasture.

  9. Carcass Search & Recovery Guidelines for Black Tailed Prairie Dogs

    Science.gov (United States)

    The availability of dead or intoxicated prairie dogs above ground will be monitored, recorded and these carcasses will be properly disposed of, in accordance with the procedures described on this page.

  10. Two decades of prairie restoration at Fermilab, Batavia, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Betz, R.F. [Northeastern Illinois Univ., Chicago, IL (United States); Lootens, R.J.; Becker, M.K. [Fermi National Accelerator Lab., Batavia, IL (United States)

    1996-12-31

    Successional Restoration is the method being used to restore the prairie at Fermilab on the former agricultural fields. This involves an initial planting, using aggressive species that have wide ecological tolerances which will grow well on abandoned agricultural fields. Collectively, these species are designated as the prairie matrix. The species used for this prairie matrix compete with and eventually eliminate most weedy species. They also provide an adequate fuel load capable of sustaining a fire within a few years after a site has been initially planted. Associated changes in the biological and physical structure of the soil help prepare the way for the successful introduction of plants of the later successional species. Only after the species of the prairie matrix are well established, is the species diversity increased by introducing species with narrower ecological tolerances. These species are thus characteristic of the later successional stages.

  11. Public knowledge and perceptions of black-tailed prairie dogs

    Science.gov (United States)

    Lamb, B.L.; Cline, K.

    2003-01-01

    Black-tailed prairie dogs (Cynomys ludovicianus) historically occupied an 11-state region of the United States. We surveyed 1,900 residents (response rate 56%) of this region to understand citizen knowledge and perceptions about prairie dogs and their management. Those who have direct experience - e.g., those who live very close to prairie dog colonies or know the location of the nearest colony - have higher levels of knowledge. A significantly higher level of knowledge was documented among those who were politically active when compared with the general public. Those who found environmental issues difficult to understand were associated with lower knowledge. People with direct experience were likely to hold negative views, whereas those holding environmentalist values were likely to express positive attitudes toward the species. Although those with higher education reported more knowledge, there was no link between a person's level of knowledge and perceptions of prairie dog management.

  12. Proceedings of the third prairie conservation and endangered species workshop

    Energy Technology Data Exchange (ETDEWEB)

    Holroyd, G.L.; Diskson, H.L.; Regnier, M.; Smith, H.C. (eds.)

    1993-01-01

    The Canadian prairies support a major agricultural economy and a declining abundance of wildlife. Soil erosion and water quality threaten the long-term viability of agriculture; half of Canada's endangered and threatened birds and mammals share the prairies. Wise policies of resource management are needed to solve these problems. A workshop was held to address the issue of how to manage the prairies to promote sustained agriculture and to conserve the wildlife that are in jeopardy. Papers were presented on the relationships between agriculture and wildlife, land restoration, climate change, pesticides, the Prairie Conservation Action Plan, plant conservation, amphibians, reptiles, migratory birds and other wildfowl, and mammals. Separate abstracts have been prepared for two papers from this workshop.

  13. Disease limits populations: plague and black-tailed prairie dogs

    Science.gov (United States)

    Cully, Jack F.; Johnson, T.; Collinge, S.K.; Ray, C.

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  14. Interspecific comparisons of sylvatic plague in prairie dogs

    Science.gov (United States)

    Cully, J.F.; Williams, E.S.

    2001-01-01

    Of the 3 major factors (habitat loss, poisoning, and disease) that limit abundance of prairie dogs today, sylvatic plague caused by Yersinia pestis is the 1 factor that is beyond human control. Plague epizootics frequently kill >99% of prairie dogs in infected colonies. Although epizootics of sylvatic plague occur throughout most of the range of prairie dogs in the United States and are well described, long-term maintenance of plague in enzootic rodent species is not well documented or understood. We review dynamics of plague in white-tailed (Cynomys leucurus), Gunnison's (C. gunnisoni), and black-tailed (C. ludovicianus) prairie dogs, and their rodent and flea associates. We use epidemiologic concepts to support an enzootic hypothesis in which the disease is maintained in a dynamic state, which requires transmission of Y. pestis to be slower than recruitment of new susceptible mammal hosts. Major effects of plague are to reduce colony size of black-tailed prairie dogs and increase intercolony distances within colony complexes. In the presence of plague, black-tailed prairie dogs will probably survive in complexes of small colonies that are usually >3 km from their nearest neighbor colonies.

  15. DESIGN OF GRASS BRIQUETTE MACHINE

    African Journals Online (AJOL)

    user

    E-mail addresses: 1 mike.ajieh@gmail.com, 2 dracigboanugo@yahoo.com, ... machine design was considered for processing biomass of grass origin. The machine operations include pulverization, compaction and extrusion of the briquettes.

  16. Breeding for Grass Seed Yield

    DEFF Research Database (Denmark)

    Boelt, Birte; Studer, Bruno

    2010-01-01

    Seed yield is a trait of major interest for many fodder and amenity grass species and has received increasing attention since seed multiplication is economically relevant for novel grass cultivars to compete in the commercial market. Although seed yield is a complex trait and affected...... by agricultural practices as well as environmental factors, traits related to seed production reveal considerable genetic variation, prerequisite for improvement by direct or indirect selection. This chapter first reports on the biological and physiological basics of the grass reproduction system, then highlights...... important aspects and components affecting the seed yield potential and the agronomic and environmental aspects affecting the utilization and realization of the seed yield potential. Finally, it discusses the potential of plant breeding to sustainably improve total seed yield in fodder and amenity grasses....

  17. Grass and weed killer poisoning

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002838.htm Grass and weed killer poisoning To use the sharing features on this page, please enable JavaScript. Many weed killers contain dangerous chemicals that are harmful if ...

  18. Environmental impact of converting Conservation Reserve Program land to perennial bioenergy crops in Illinois.

    Science.gov (United States)

    Blanc-Betes, E.; Hudiburg, T. W.; Khanna, M.; DeLucia, E. H.

    2017-12-01

    Reducing dependence on fossil fuels by the 20% by 2022 mandated by the Energy Independence and Security Act would require 35 billion Ga of ethanol and the loss of 9 to 12 Mha of food producing land to biofuel production, challenging our ability to develop a sustainable bioenergy source while meeting the food demands of a growing population. There are currently 8.5 Mha of land enrolled in the Conservation Reserve Program (CRP), a US government funded program to incentivize the retirement of environmentally sensitive cropland out of conventional crop production. About 63% of CRP land area could potentially be converted to energy crops, contributing to biofuel targets without displacing food. With high yields and low fertilization and irrigation requirements, perennial cellulosic crops (e.g. switchgrass and Miscanthus) not only would reduce land requirements by up to 15% compared to prairies or corn-based biofuel, but also serve other conservation goals such as C sequestration in soils, and water and air quality improvement. Here, we use the DayCent biogeochemical model to assess the potential of CRP land conversion to switchgrass or Miscanthus to provide a sustainable source of biofuel, reduce GHG emissions and increase soil organic carbon (SOC) storage in the area of Illinois, which at present contributes to 10% of the biofuel production in the US. Model simulations indicate that the replacement of traditional corn-soy rotation with CRP reduces GHG emissions by 3.3 Mg CO2-eq ha-1 y-1 and increases SOC storage at a rate of 0.5 Mg C ha-1 y-1. Conversion of CRP land to cellulosic perennials would further reduce GHG emissions by 1.1 Mg CO2-eq ha-1 y-1 for switchgrass and 6.2 Mg CO2-eq ha-1 y-1 for Miscanthus, and increase C sequestration in soils (1.7 Tg C for switchgrass and 7.7 Tg C for Miscanthus in 30 years). Cellulosic energy crops would increase average annual yields by approximately 5.6 Mg ha-1 for switchgrass and 13.6 Mg ha-1 for Miscanthus, potentially

  19. Effects of dairy manure management in annual and perennial cropping systems on soil microbial communities associated with in situ N2O fluxes

    Science.gov (United States)

    Dunfield, Kari; Thompson, Karen; Bent, Elizabeth; Abalos, Diego; Wagner-Riddle, Claudia

    2016-04-01

    Liquid dairy manure (LDM) application and ploughing events may affect soil microbial community functioning differently between perennial and annual cropping systems due to plant-specific characteristics stimulating changes in microbial community structure. Understanding how these microbial communities change in response to varied management, and how these changes relate to in situ N2O fluxes may allow the creation of predictive models for use in the development of best management practices (BMPs) to decrease nitrogen (N) losses through choice of crop, plough, and LDM practices. Our objectives were to contrast changes in the population sizes and community structures of genes associated with nitrifier (amoA, crenamoA) and denitrifier (nirK, nirS, nosZ) communities in differently managed annual and perennial fields demonstrating variation in N2O flux, and to determine if differences in these microbial communities were linked to the observed variation in N2O fluxes. Soil was sampled in 2012 and in 2014 in a 4-ha spring-applied LDM grass-legume (perennial) plot and two 4-ha corn (annual) treatments under fall or spring LDM application. Soil DNA was extracted and used to target N-cycling genes via qPCR (n=6) and for next-generation sequencing (Illumina Miseq) (n=3). Significantly higher field-scale N2O fluxes were observed in the annual plots compared to the perennial system; however N2O fluxes increased after plough down of the perennial plot. Nonmetric multidimensional scaling (NMS) indicated differences in N-cycling communities between annual and perennial cropping systems, and some communities became similar between annual and perennial plots after ploughing. Shifts in these communities demonstrated relationships with agricultural management, which were associated with differences in N2O flux. Indicator species analysis was used to identify operational taxonomic units (OTUs) most responsible for community shifts related to management. Nitrifying and denitrifying soil

  20. Herbaceous Legume Encroachment Reduces Grass Productivity and Density in Arid Rangelands.

    Directory of Open Access Journals (Sweden)

    Thomas C Wagner

    Full Text Available Worldwide savannas and arid grasslands are mainly used for livestock grazing, providing livelihood to over a billion people. While normally dominated by perennial C4 grasses, these rangelands are increasingly affected by the massive spread of native, mainly woody legumes. The consequences are often a repression of grass cover and productivity, leading to a reduced carrying capacity. While such encroachment by woody plants has been extensively researched, studies on similar processes involving herbaceous species are rare. We studied the impact of a sustained and massive spread of the native herbaceous legume Crotalaria podocarpa in Namibia's escarpment region on the locally dominant fodder grasses Stipagrostis ciliata and Stipagrostis uniplumis. We measured tussock densities, biomass production of individual tussocks and tussock dormancy state of Stipagrostis on ten 10 m x 10 m plots affected and ten similarly-sized plots unaffected by C. podocarpa over eight consecutive years and under different seasonal rainfalls and estimated the potential relative productivity of the land. We found the percentage of active Stipagrostis tussocks and the biomass production of individual tussocks to increase asymptotically with higher seasonal rainfall reaching a maximum around 300 mm while the land's relative productivity under average local rainfall conditions reached only 40% of its potential. Crotalaria podocarpa encroachment had no effect on the proportion of productive grass tussocks, but reduced he productivity of individual Stipagrostis tussocks by a third. This effect of C. podocarpa on grass productivity was immediate and direct and was not compensated for by above-average rainfall. Besides this immediate effect, over time, the density of grass tussocks declined by more than 50% in areas encroached by C. podocarpa further and lastingly reducing the lands carrying capacity. The effects of C. podocarpa on grass productivity hereby resemble those of woody

  1. High green fodder yielding new grass varieties

    OpenAIRE

    C. Babu, K. Iyanar and A. Kalamani

    2014-01-01

    Two high biomass yielding forage grass varieties one each in Cumbu Napier hybrid and Guinea grass have been evolved at the Department of Forage Crops, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore and identified for release at national (All India) level as Cumbu Napier hybrid grass CO (BN) 5 and Guinea grass CO (GG) 3 during 2012 and 2013 respectively. Cumbu Napier hybrid grass CO (BN) 5 secured first rank at all national level with reference to green ...

  2. A meta-analysis of lesser prairie-chicken nesting and brood-rearing habitats: implications for habitat management

    Science.gov (United States)

    Hagen, Christian A.; Grisham, Blake A.; Boal, Clint W.; Haukos, David A.

    2013-01-01

    The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands. As a candidate for protection under the Endangered Species Act, there is a need for a synthesis that characterizes habitat structure rangewide. Thus, we conducted a meta-analysis of vegetation characteristics at nest sites and brood habitats to determine whether there was an overall effect (Hedges' d) of habitat selection and to estimate average (95% CI) habitat characteristics at use sites. We estimated effect sizes (di) from the difference between use (nests and brood sites) and random sampling sites for each study (n = 14), and derived an overall effect size (d++). There was a general effect for habitat selection as evidenced by low levels of variation in effect sizes across studies and regions. There was a small to medium effect (d++) = 0.20-0.82) of selection for greater vertical structure (visual obstruction) by nesting females in both vegetation communities, and selection against bare ground (d++ = 0.20-0.58). Females with broods exhibited less selectivity for habitat components except for vertical structure. The variation of d++ was greater during nesting than brooding periods, signifying a seasonal shift in habitat use, and perhaps a greater range of tolerance for brood-rearing habitat. The overall estimates of vegetation cover were consistent with those provided in management guidelines for the species.

  3. Grass-Shrub Associations over a Precipitation Gradient and Their Implications for Restoration in the Great Basin, USA.

    Directory of Open Access Journals (Sweden)

    Maike F Holthuijzen

    Full Text Available As environmental stress increases positive (facilitative plant interactions often predominate. Plant-plant associations (or lack thereof can indicate whether certain plant species favor particular types of microsites (e.g., shrub canopies or plant-free interspaces and can provide valuable insights into whether "nurse plants" will contribute to seeding or planting success during ecological restoration. It can be difficult, however, to anticipate how relationships between nurse plants and plants used for restoration may change over large-ranging, regional stress gradients. We investigated associations between the shrub, Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis, and three common native grasses (Poa secunda, Elymus elymoides, and Pseudoroegneria spicata, representing short-, medium-, and deep-rooted growth forms, respectively, across an annual rainfall gradient (220-350 mm in the Great Basin, USA. We hypothesized that positive shrub-grass relationships would become more frequent at lower rainfall levels, as indicated by greater cover of grasses in shrub canopies than vegetation-free interspaces. We sampled aerial cover, density, height, basal width, grazing status, and reproductive status of perennial grasses in canopies and interspaces of 25-33 sagebrush individuals at 32 sites along a rainfall gradient. We found that aerial cover of the shallow rooted grass, P. secunda, was higher in sagebrush canopy than interspace microsites at lower levels of rainfall. Cover and density of the medium-rooted grass, E. elymoides were higher in sagebrush canopies than interspaces at all but the highest rainfall levels. Neither annual rainfall nor sagebrush canopy microsite significantly affected P. spicata cover. E. elymoides and P. spicata plants were taller, narrower, and less likely to be grazed in shrub canopy microsites than interspaces. Our results suggest that exploring sagebrush canopy microsites for restoration of native perennial

  4. Changes in nutritive value and herbage yield during extended growth intervals in grass-legume mixtures

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2018-01-01

    . Perennial ryegrass was sown with each of four legumes: red clover, white clover, lucerne and birdsfoot trefoil, and white clover was sown with hybrid ryegrass, meadow fescue and timothy. Effects of species composition on herbage yield, contents of N, neutral detergent fibre (NDF), acid detergent fibre (ADF...... in quality parameters differed among species and functional groups, i.e., grasses and legumes. Results are discussed in the context of quantifying the impact of delaying the harvest date of grass–legume mixtures and relationships between productivity and components of feed quality....

  5. Black-tailed prairie dogs, cattle, and the conservation of North America's arid grasslands.

    Directory of Open Access Journals (Sweden)

    Rodrigo Sierra-Corona

    Full Text Available Prairie dogs (Cynomys spp. have been eliminated from over 95% of their historic range in large part from direct eradication campaigns to reduce their purported competition with cattle for forage. Despite the longstanding importance of this issue to grassland management and conservation, the ecological interactions between cattle and prairie dogs have not been well examined. We address this issue through two complementary experiments to determine if cattle and prairie dogs form a mutualistic grazing association similar to that between prairie dogs and American bison. Our experimental results show that cattle preferentially graze along prairie dog colony edges and use their colony centers for resting, resembling the mutualistic relationship prairie dogs have with American bison. Our results also show that prairie dog colonies are not only an important component of the grassland mosaic for maintaining biodiversity, but also provide benefits to cattle, thereby challenging the long-standing view of prairie dogs as an undesirable pest species in grasslands.

  6. Validation of reference genes for quantitative RT-PCR studies of gene expression in perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Thrush Anthony

    2010-01-01

    Full Text Available Abstract Background Perennial ryegrass (Lolium perenne L. is an important pasture and turf crop. Biotechniques such as gene expression studies are being employed to improve traits in this temperate grass. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR is among the best methods available for determining changes in gene expression. Before analysis of target gene expression, it is essential to select an appropriate normalisation strategy to control for non-specific variation between samples. Reference genes that have stable expression at different biological and physiological states can be effectively used for normalisation; however, their expression stability must be validated before use. Results Existing Serial Analysis of Gene Expression data were queried to identify six moderately expressed genes that had relatively stable gene expression throughout the year. These six candidate reference genes (eukaryotic elongation factor 1 alpha, eEF1A; TAT-binding protein homolog 1, TBP-1; eukaryotic translation initiation factor 4 alpha, eIF4A; YT521-B-like protein family protein, YT521-B; histone 3, H3; ubiquitin-conjugating enzyme, E2 were validated for qRT-PCR normalisation in 442 diverse perennial ryegrass (Lolium perenne L. samples sourced from field- and laboratory-grown plants under a wide range of experimental conditions. Eukaryotic EF1A is encoded by members of a multigene family exhibiting differential expression and necessitated the expression analysis of different eEF1A encoding genes; a highly expressed eEF1A (h, a moderately, but stably expressed eEF1A (s, and combined expression of multigene eEF1A (m. NormFinder identified eEF1A (s and YT521-B as the best combination of two genes for normalisation of gene expression data in perennial ryegrass following different defoliation management in the field. Conclusions This study is unique in the magnitude of samples tested with the inclusion of numerous field-grown samples

  7. Sustainable Production of Switchgrass for Biomass Energy

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a C4 grass native to the North American tallgrass prairies, which historically extended from Mexico to Canada. It is the model perennial warm-season grass for biomass energy. USDA-ARS in Lincoln, NE has studied switchgrass continuously since 1936. Plot-scale rese...

  8. Effect of substituting fresh-cut perennial ryegrass with fresh-cut white clover on bovine milk fatty acid profile.

    Science.gov (United States)

    Stergiadis, Sokratis; Hynes, Deborah N; Thomson, Anna L; Kliem, Kirsty E; Berlitz, Carolina Gb; Günal, Mevlüt; Yan, Tianhai

    2018-03-06

    Including forage legumes in dairy systems can help address increasing environmental/economic concerns about perennial ryegrass monoculture pastures. This work investigated the effect of substituting fresh-cut grass with increasing quantities of fresh-cut white clover (WC) on milk fatty acid (FA) profile and transfer efficiency of dietary linoleic (LA) and α-linolenic (ALNA) acids to milk fat. Three groups of three crossbred dairy cows were used in a 3 × 3 crossover design. Dietary treatments were 0 g kg -1 WC + 600 g kg -1 grass, 200 g kg -1 WC + 400 g kg -1 grass, and 400 g kg -1 WC + 200 g kg -1 grass. All treatments were supplemented with 400 g kg -1 concentrates on a dry matter basis. Cows had a 19-day adaptation period to the experimental diet before a 6-day measurement period in individual tie stalls. Increasing dietary WC did not affect dry matter intake, milk yield or milk concentrations of fat, protein or lactose. Milk polyunsaturated FA concentrations (total n-3, total n-6, LA and ALNA) and transfer efficiency of LA and ALNA were increased with increasing dietary WC supply. Inclusion of WC in pastures may increase concentrations of nutritionally beneficial FA, without influencing milk yield and basic composition, but any implications on human health cannot be drawn. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

  9. Variation in the expression of ergot alkaloids between individual tillers of perennial ryegrass

    Science.gov (United States)

    Mace, Wade; Lunn, Kristy; Lloyd-West, Catherine

    2014-11-01

    Epichloë fungal endophytes of cool season grasses are well known to produce a range of alkaloids of benefit to the host. Some of these compounds are advantageous to agriculture due to qualities that promote pasture persistence (e.g. the loline class of alkaloids confer insect protection) while others are detrimental to the wellbeing of grazing livestock. The ergot alkaloids (e.g. ergovaline), produced in ryegrass and tall fescue associations, causes poor animal health in farming regions in many countries around the world and further study is required to improve our knowledge on this class of compounds. Here we present the application of a quantitative LC-MS/MS (liquid chromatography coupled to mass spectrometry) method measuring eight ergot alkaloids (chanoclavine, agroclavine, elymoclavine, lysergol, lysergic acid, ergine, lysergyl alanine, ergovaline) produced by endophyte infected grasses, to monitor levels in individual tillers from multiple plants of a single cultivar of perennial ryegrass (Lolium perenne cv. ‘Grasslands Samson’) infected with a common toxic endophyte strain (Epichloë festucae var. lolii). Monitoring the expression in individual tillers allows an estimation of the variability within a plant (between tillers) as well as between plants. The study showed that there is significant variation in the concentration of the ergot alkaloids between tillers of a single plant, at or exceeding the level of variation observed between individual plants of a population. This result emphasizes the fundamental importance of robust experimental design and sampling procedures when alkaloid expression assessment is required and these need to be rigorously tailored to the hypothesis being tested.

  10. Variation in the expression of ergot alkaloids between individual tillers of perennial ryegrass

    Directory of Open Access Journals (Sweden)

    Wade Jeffray Mace

    2014-11-01

    Full Text Available Epichloë fungal endophytes of cool season grasses are well known to produce a range of alkaloids of benefit to the host. Some of these compounds are advantageous to agriculture due to qualities that promote pasture persistence (e.g. the loline class of alkaloids confer insect protection while others are detrimental to the wellbeing of grazing livestock. The ergot alkaloids (e.g. ergovaline, produced in ryegrass and tall fescue associations, causes poor animal health in farming regions in many countries around the world and further study is required to improve our knowledge on this class of compounds. Here we present the application of a quantitative LC-MS/MS (liquid chromatography coupled to mass spectrometry method measuring eight ergot alkaloids (chanoclavine, agroclavine, elymoclavine, lysergol, lysergic acid, ergine, lysergyl alanine, ergovaline produced by endophyte infected grasses, to monitor levels in individual tillers from multiple plants of a single cultivar of perennial ryegrass (Lolium perenne cv. ‘Grasslands Samson’ infected with a common toxic endophyte strain (Epichloë festucae var. lolii. Monitoring the expression in individual tillers allows an estimation of the variability within a plant (between tillers as well as between plants.The study showed that there is significant variation in the concentration of the ergot alkaloids between tillers of a single plant, at or exceeding the level of variation observed between individual plants of a population. This result emphasizes the fundamental importance of robust experimental design and sampling procedures when alkaloid expression assessment is required and these need to be rigorously tailored to the hypothesis being tested.

  11. Totally impermeable film (TIF reduces emissions in perennial crop fumigation

    Directory of Open Access Journals (Sweden)

    Suduan Gao

    2013-10-01

    Full Text Available Many perennial nursery fields and replanted orchards and vineyards in California are treated with preplant soil fumigants to control soilborne pests. In annual crops, such as strawberry, covering fumigated fields with totally impermeable film (TIF has shown promise in controlling emissions and improving fumigant distribution in soil. The objective of this research was to optimize the use of TIF for perennial crops via three field trials. TIF reduced peak emission flux and cumulative emissions by > 90% relative to polyethylene tarp during a 2-week covering period. After the TIF was cut, emissions were greatly reduced compared to when tarps were cut after 6 days. TIF maintained higher fumigant concentrations under tarp and in the soil than polyethylene film. The results indicate that TIF can increase fumigation efficiency for perennial crop growers.

  12. Small mammals in successional prairie woodlands of the northern Great Plains

    Science.gov (United States)

    Mark A. Rumble; John E. Gobeille

    2001-01-01

    Prairie woodlands comprise about 1 percent of the landscape in the northern Great Plains. However, prairie woodlands provide habitat for far more than 1 percent of the wildlife species that occur in the prairie region. With increasing pressures on natural resources, managers need methods for managing wildlife habitat and biodiversity that are based on ecological...

  13. 76 FR 77245 - Attwater Prairie Chicken National Wildlife Refuge, Austin and Colorado Counties, TX...

    Science.gov (United States)

    2011-12-12

    ...-FF02R06000] Attwater Prairie Chicken National Wildlife Refuge, Austin and Colorado Counties, TX... (EA) for Attwater Prairie Chicken National Wildlife Refuge (Refuge, NWR), located approximately 60... Prairie Chicken NWR draft CCP and EA'' in the subject line of the message. Fax: Attn: Monica Kimbrough...

  14. 75 FR 21649 - Endangered and Threatened Wildlife and Plants; Attwater's Prairie-Chicken (Tympanuchus cupido...

    Science.gov (United States)

    2010-04-26

    ...] Endangered and Threatened Wildlife and Plants; Attwater's Prairie-Chicken (Tympanuchus cupido attwateri... availability of the Attwater's Prairie-Chicken (Tympanuchus cupido attwateri) Recovery Plan, Second Revision. A recovery plan was originally completed for the Attwater's prairie-chicken in 1983 and revised in 1993...

  15. Assessing Water-use Relationships in a Perennial Kernza Field

    Science.gov (United States)

    De Oliveira, G.; Brunsell, N. A.; Sutherlin, C. E.; Crews, T.; Vico, G.

    2017-12-01

    Perennial grain/forage crops can sustain high yields without replanting for 3-10 years or more, resulting in potentially important environmental benefits. Although previous research has been conducted in perennial food crops, the coupling between these ecosystems and the atmosphere is not well understood. The objective of this study was to evaluate the magnitude and temporal variability of the water-use relationships in a perennial Kernza wheatgrass crop in Salina, north-central region of Kansas (KS), USA. The study period comprised approximately 4.5 years (May 2012-October 2016) of eddy covariance observations collected at the US-KLS AmeriFlux tower. In particular, we examine the water-use efficiency, carbon and water fluxes in relation to the local environmental factors, such as vapor pressure deficit, soil moisture, air temperature, etc. An analysis of the correspondence between accumulated precipitation (PPT) and ET in the perennial crop indicated a most likely low surface runoff and that there were other sources of water for plant intake in addition to the annual PPT, i.e., deep water. In this sense, we highlight that the long roots observed in perennial crops may facilitate the water uptake in the deeper soil layers, providing extra resources for the plant growth especially when the rainfall indices are low. The results obtained in this work are important in order to better understand the hydrologic cycle of perennial agroecosystems as well as to understand the benefits and disadvantages in relation to annual crops particularly under changing climatic conditions.

  16. Vulnerability of shortgrass prairie bird assemblages to climate change

    Science.gov (United States)

    Skagen, Susan K.; Dreitz, Victoria; Conrey, Reesa Y.; Yackel, Amy; Panjabi, Arvind O.; Knuffman, Lekha

    2016-01-01

    The habitats and resources needed to support grassland birds endemic to North American prairie ecosystems are seriously threatened by impending climate change. To assess the vulnerability of grassland birds to climate change, we consider various components of vulnerability, including sensitivity, exposure, and adaptive capacity (Glick et al. 2011). Sensitivity encompasses the innate characteristics of a species and, in this context, is related to a species’ tolerance to changes in weather patterns. Groundnesting birds, including prairie birds, are particularly responsive to heat waves combined with drought conditions, as revealed by abundance and distribution patterns (Albright et al. 2010). To further assess sensitivity, we estimated reproductive parameters of nearly 3000 breeding attempts of a suite of prairie birds relative to prevailing weather. Fluctuations in weather conditions in eastern Colorado, 1997-2014, influenced breeding performance of a suite of avian species endemic to the shortgrass prairie, many of which have experienced recent population declines. High summer temperatures and intense rain events corresponded with lower nest survival for most species. Although dry conditions favored nest survival of Burrowing Owls and Mountain Plovers (Conrey 2010, Dreitz et al. 2012), drought resulted in smaller clutch sizes and lower nest survival for passerines (Skagen and Yackel Adams 2012, Conrey et al. in review). Declining summer precipitation may reduce the likelihood that some passerine species can maintain stable breeding populations in this region of the shortgrass prairie.

  17. Prairie dogs increase fitness by killing interspecific competitors.

    Science.gov (United States)

    Hoogland, John L; Brown, Charles R

    2016-03-30

    Interspecific competition commonly selects for divergence in ecology, morphology or physiology, but direct observation of interspecific competition under natural conditions is difficult. Herbivorous white-tailed prairie dogs (Cynomys leucurus) employ an unusual strategy to reduce interspecific competition: they kill, but do not consume, herbivorous Wyoming ground squirrels (Urocitellus elegans) encountered in the prairie dog territories. Results from a 6-year study in Colorado, USA, revealed that interspecific killing of ground squirrels by prairie dogs was common, involving 47 different killers; 19 prairie dogs were serial killers in the same or consecutive years, and 30% of female prairie dogs killed at least one ground squirrel over their lifetimes. Females that killed ground squirrels had significantly higher annual and lifetime fitness than non-killers, probably because of decreased interspecific competition for vegetation. Our results document the first case of interspecific killing of competing individuals unrelated to predation (IK) among herbivorous mammals in the wild, and show that IK enhances fitness for animals living under natural conditions. © 2016 The Author(s).

  18. Simulation of biomass yield of regular and chilling tolerant Miscanthus cultivars and reed canary grass in different climates of Europe

    DEFF Research Database (Denmark)

    Kandel, Tanka Prasad; Hastings, Astley; Jørgensen, Uffe

    2016-01-01

    Miscanthus and reed canary grass (RCG) are C4 and C3 perennial grasses which are popular in Europe as energy crops. Although Miscanthus is relatively chilling tolerant compared to other C4 species, its production in northern Europe is still constrained by cold temperature. A more chilling tolerant...... Miscanthus cultivar which can emerge early in the spring would utilize more solar radiation and produce higher biomass yields. In this study, using MiscanFor model, we estimated potential biomass yield of Miscanthus in current and future climates with the assumption that breeding would provide a chilling...

  19. Reproductive effort of some annual and perennial plant species: impact of successional sequence, habitat conditions and plant size

    International Nuclear Information System (INIS)

    Shaukat, S.; Khan, M.A.; Zaidi, S.; Siddiqui, M.F.; Khan, N.; Zafar, H.

    2013-01-01

    The reproductive effort of some annual and perennial plant species was investigated with respect to successional sequence, habitat conditions and plant size. in the psammosere succession (dune succession), the reproductive effort (RE) of Cressa cretica and A triplex griffithii was significantly greater in the early stage compared to that in late succession. Likewise, in relation to lithosere succession, Sporobolus arabicus. Pluchea lanceolata and Vernonia cenerescens all showed high reproductive effort in early part of succession compared to that of late succession. The annuals (S. arabicus and P lance/ala) exhibited greater reproductive effort compared to the perennial species Vernonia cinerescens. Examination of the Impact of site differences on reproductive effort showed that four grasses including Selaria intermedia, Chioris harbata, Cenchrus hiflorus, and Eragroslis pilosa were found to have significantly (P<0.05) greater reproductive effort in site 1 (near cultivated field), compared to site 2 (a vacant lot), which had low nutrient level compared to site 1. The reproductive effort of Sonclius asper (a composite) did not exhibit significant difference between sites. The investigation of relationships between plant size (volume) and reproductive effort of Solanuin forskalii, Senna holosericea and Heliolropium ophioglossum showed positive correlations between plant size and reproductive effort. Solanum forskalii and Senna holosericca, in particular, exhibited a close association in this respect. It is concluded that: 1) RE is greater in early compared to late succession, 2) RE changes with the habitat and 3) there seems to be a direct relationship between RE and plant size. (author)

  20. Invertebrate populations in miscanthus (Miscanthusxgiganteus) and reed canary-grass (Phalaris arundinacea) fields

    Energy Technology Data Exchange (ETDEWEB)

    Semere, T.; Slater, F.M. [Llysdinam Field Centre, School of Biosciences, Cardiff University, Newbridge-on-Wye, Llandrindod Wells, Powys, LD1 6NB (United Kingdom)

    2007-01-15

    Monitoring of invertebrates at four field sites in Herefordshire, England, growing miscanthus and reed canary-grass was carried out in 2002, 2003 and 2004 to investigate the ecological impact of these crops on ground beetles, butterflies and arboreal invertebrates. Ground beetles were sampled by pitfall trapping; and arboreal invertebrates by sweep netting and stem beating. The Centre for Ecology and Hydrology's Butterflies Monitoring Scheme methodology was used to record butterflies. The effects of the biomass crops on invertebrates were indirect, through the use of weeds as food resources and habitat. The greater diversity of weed flora within miscanthus fields than within reed canary-grass fields had a greater positive effect on invertebrates. Ground beetles, butterflies and arboreal invertebrates were more abundant and diverse in the most floristically diverse miscanthus fields. The difference in crop architecture and development between miscanthus and reed canary-grass was reflected in their differences in crop height and ground cover early on in the season. However, most of the difference in arthropod abundance between the two crops was attributed to the difference in the agronomic practice of growing the crops such as plant density, and the effect of this on weed growth. Since perennial rhizomatous grasses require a single initial planting and related tillage, and also no major chemical inputs; and because the crops are harvested in the spring and the land is not disturbed by cultivation every year, the fields were used as over-wintering sites for invertebrates suggesting immediate benefits to biodiversity. (author)

  1. Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

    Science.gov (United States)

    Moran, Matthew D

    2014-10-01

    How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity.

  2. Cell wall composition throughout development for the model grass Brachypodium distanchyon

    Directory of Open Access Journals (Sweden)

    David eRancour

    2012-12-01

    Full Text Available Temperate perennial grasses are important worldwide as a livestock nutritive energy source and a potential feedstock for lignocellulosic biofuel production. The annual temperate grass Brachypodium distanchyon has been championed as a useful model system to facilitate biological research in agriculturally important temperate forage grasses based on phylogenetic relationships. To physically corroborate genetic predictions, we determined the chemical composition profiles of organ-specific cell walls throughout the development of two common diploid accessions of Brachypodium distanchyon, Bd21-3 and Bd21. Chemical analysis was performed on cell walls isolated from distinct organs (i.e. leaves, sheaths, stems and roots at three developmental stages of 1 12-day seedling, 2 vegetative-to-reproductive transition, and 3 mature seed-fill. In addition, we have included cell wall analysis of embryonic callus used for genetic transformations. Composition of cell walls based on components lignin, hydroxycinnamates, uronosyls, neutral sugars, and protein suggests that Brachypodium distanchyon is similar chemically to agriculturally important forage grasses. There were modest compositional differences in hydroxycinnamate profiles between accessions Bd21-3 and Bd21. In addition, when compared to agronomical important C3 grasses, more mature Brachypodium stem cell walls have a relative increase in glucose of 48% and a decrease in lignin of 36%. Though differences exists between Brachypodium and agronomical important C3 grasses, Brachypodium distanchyon should be still a useful model system for genetic manipulation of cell wall composition to determine the impact upon functional characteristics such as rumen digestibility or energy conversion efficiency for bioenergy production.

  3. Cell wall composition throughout development for the model grass Brachypodium distachyon

    Science.gov (United States)

    Rancour, David M.; Marita, Jane M.; Hatfield, Ronald D.

    2012-01-01

    Temperate perennial grasses are important worldwide as a livestock nutritive energy source and a potential feedstock for lignocellulosic biofuel production. The annual temperate grass Brachypodium distachyon has been championed as a useful model system to facilitate biological research in agriculturally important temperate forage grasses based on phylogenetic relationships. To physically corroborate genetic predictions, we determined the chemical composition profiles of organ-specific cell walls throughout the development of two common diploid accessions of Brachypodium distachyon, Bd21-3 and Bd21. Chemical analysis was performed on cell walls isolated from distinct organs (i.e., leaves, sheaths, stems, and roots) at three developmental stages of (1) 12-day seedling, (2) vegetative-to-reproductive transition, and (3) mature seed fill. In addition, we have included cell wall analysis of embryonic callus used for genetic transformations. Composition of cell walls based on components lignin, hydroxycinnamates, uronosyls, neutral sugars, and protein suggests that Brachypodium distachyon is similar chemically to agriculturally important forage grasses. There were modest compositional differences in hydroxycinnamate profiles between accessions Bd21-3 and Bd21. In addition, when compared to agronomical important C3 grasses, more mature Brachypodium stem cell walls have a relative increase in glucose of 48% and a decrease in lignin of 36%. Though differences exist between Brachypodium and agronomical important C3 grasses, Brachypodium distachyon should be still a useful model system for genetic manipulation of cell wall composition to determine the impact upon functional characteristics such as rumen digestibility or energy conversion efficiency for bioenergy production. PMID:23227028

  4. Spent fuel storage at Prairie Island: January 1995 status

    International Nuclear Information System (INIS)

    Closs, J.; Kress, L.

    1995-01-01

    The disposal of spent nuclear fuel has been an issue for the US since the inception of the commercial nuclear power industry. In the past decade, it has become a critical factor in the continued operation of some nuclear power plants, including the two units at Prairie Island. As the struggles and litigation over storage alternatives wage on, spent fuel pools continue to fill and plants edge closer to premature shutdown. Due to the delays in the construction of a federal repository, many nuclear power plants have had to seek interim storage alternatives. In the case of Prairie Island, the safest and most feasible option is dry cask storage. This paper discusses the current status of the Independent Spent Fuel Storage Installation (ISFSI) Project at Prairie Island. It provides a historical background to the project, discusses the notable developments over the past year, and presents the projected plans of the Northern States Power Company (NSP) in regards to spent fuel storage

  5. Complete chloroplast genome sequence of a major allogamous forage species, perennial ryegrass (Lolium perenne L.).

    Science.gov (United States)

    Diekmann, Kerstin; Hodkinson, Trevor R; Wolfe, Kenneth H; van den Bekerom, Rob; Dix, Philip J; Barth, Susanne

    2009-06-01

    Lolium perenne L. (perennial ryegrass) is globally one of the most important forage and grassland crops. We sequenced the chloroplast (cp) genome of Lolium perenne cultivar Cashel. The L. perenne cp genome is 135 282 bp with a typical quadripartite structure. It contains genes for 76 unique proteins, 30 tRNAs and four rRNAs. As in other grasses, the genes accD, ycf1 and ycf2 are absent. The genome is of average size within its subfamily Pooideae and of medium size within the Poaceae. Genome size differences are mainly due to length variations in non-coding regions. However, considerable length differences of 1-27 codons in comparison of L. perenne to other Poaceae and 1-68 codons among all Poaceae were also detected. Within the cp genome of this outcrossing cultivar, 10 insertion/deletion polymorphisms and 40 single nucleotide polymorphisms were detected. Two of the polymorphisms involve tiny inversions within hairpin structures. By comparing the genome sequence with RT-PCR products of transcripts for 33 genes, 31 mRNA editing sites were identified, five of them unique to Lolium. The cp genome sequence of L. perenne is available under Accession number AM777385 at the European Molecular Biology Laboratory, National Center for Biotechnology Information and DNA DataBank of Japan.

  6. Rhetorical Transcendence Revisited: The "Thin Red Line" as Perennial Philosophy.

    Science.gov (United States)

    Stroud, Scott R.

    Fifteen years ago, J. H. Rushing published a seminal article addressing the fragmentation within contemporary society and the ways in which myths (films) may address this exigence. The exigence of fragmentation is relieved, according to her analysis, by mediated recourse to the perennial philosophy of monistic holism that is found across the…

  7. The occurrence of large branchiopod crustaceans in perennial pans ...

    African Journals Online (AJOL)

    Pans are isolated, shallow depressions that are endorheic in nature. Because of the natural hydrological functioning of pans, these systems are usually restricted to arid regions and complete desiccation occurs seasonally. In the eastern provinces of South Africa many pans are perennial in nature often remaining inundated ...

  8. Transgenic perennial biofuel feedstocks and strategies for bioconfinement

    Science.gov (United States)

    The use of transgenic tools for the improvement of plant feedstocks will be required to realize the full economic and environmental benefits of cellulosic and other biofuels, particularly from perennial plants. Traits that are targets for improvement of biofuels crops include he...

  9. Tier 2 guidelines and remediation of Tebuthiuron on a native prairie site

    Energy Technology Data Exchange (ETDEWEB)

    Bessie, K.; Harckham, N.; Dance, T. [EBA Engineering Consultants Ltd., Calgary, AB (Canada); Burk, A. [EnCana Corp., Calgary, AB (Canada); Stephenson, G. [Stantec Consulting, Guelph, ON (Canada); Corbet, B. [Access Analytical Laboratories Inc., Calgary, AB (Canada)

    2009-10-01

    Tebuthiuron is a sterilant used to control vegetation at upstream and midstream petroleum sites. This article discussed the remediation processes used to reclaim a native prairie site contaminated with tebuthiuron. The site was located within a dry mixed grass natural area. A literature review was conducted to establish soil eco-contact guidelines specific to tebuthiuron. A site-specific ecotoxicity assessment was then conducted using a liquid chromatograph to detect tebuthiuron limits in the contaminated soils. A soil sampling technique was used to delineate the affected areas at the site. Site soils were spiked with various concentrations of tebuthiuron ranging from 0.00003 mg/kg to 3000 mg/kg. Test species included a Folsomia candida, an earthworm, and 4 plant species. The study showed that the invertebrate species were less sensitive to tebuthiuron than the plant species. A groundwater assessment showed that tebuthiuron levels exceeded Tier 1 groundwater remediation guidelines. A multilayer hydro-geological model showed that remediation guidelines were orders of magnitude greater than Tier 1 groundwater remediation. A thermal desorption technique was used to remediate the site. 7 refs., 8 figs.

  10. Paltry past-precipitation: Predisposing prairie dogs to plague?

    Science.gov (United States)

    Eads, David; Biggins, Dean E.

    2017-01-01

    The plague bacterium Yersinia pestis was introduced to California in 1900 and spread rapidly as a sylvatic disease of mammalian hosts and flea vectors, invading the Great Plains in the United States by the 1930s to 1940s. In grassland ecosystems, plague causes periodic, devastating epizootics in colonies of black-tailed prairie dogs (Cynomys ludovicianus), sciurid rodents that create and maintain subterranean burrows. In doing so, plague inhibits prairie dogs from functioning as keystone species of grassland communities. The rate at which fleas transmit Y. pestis is thought to increase when fleas are abundant. Flea densities can increase during droughts when vegetative production is reduced and herbivorous prairie dogs are malnourished and have weakened defenses against fleas. Epizootics of plague have erupted frequently in prairie dogs during years in which precipitation was plentiful, and the accompanying cool temperatures might have facilitated the rate at which fleas transmitted Y. pestis. Together these observations evoke the hypothesis that transitions from dry-to-wet years provide conditions for plague epizootics in prairie dogs. Using generalized linear models, we analyzed a 24-year dataset on the occurrence of plague epizootics in 42 colonies of prairie dogs from Colorado, USA, 1982–2005. Of the 33 epizootics observed, 52% erupted during years with increased precipitation in summer. For the years with increased summer precipitation, if precipitation in the prior growing season declined from the maximum of 502 mm to the minimum of 200 mm, the prevalence of plague epizootics was predicted to increase 3-fold. Thus, reduced precipitation may have predisposed prairie dogs to plague epizootics when moisture returned. Biologists sometimes assume dry conditions are detrimental for plague. However, 48% of epizootics occurred during years in which precipitation was scarce in summer. In some cases, an increased abundance of fleas during dry years might

  11. Estimated Perennial Streams of Idaho and Related Geospatial Datasets

    Science.gov (United States)

    Rea, Alan; Skinner, Kenneth D.

    2009-01-01

    The perennial or intermittent status of a stream has bearing on many regulatory requirements. Because of changing technologies over time, cartographic representation of perennial/intermittent status of streams on U.S. Geological Survey (USGS) topographic maps is not always accurate and (or) consistent from one map sheet to another. Idaho Administrative Code defines an intermittent stream as one having a 7-day, 2-year low flow (7Q2) less than 0.1 cubic feet per second. To establish consistency with the Idaho Administrative Code, the USGS developed regional regression equations for Idaho streams for several low-flow statistics, including 7Q2. Using these regression equations, the 7Q2 streamflow may be estimated for naturally flowing streams anywhere in Idaho to help determine perennial/intermittent status of streams. Using these equations in conjunction with a Geographic Information System (GIS) technique known as weighted flow accumulation allows for an automated and continuous estimation of 7Q2 streamflow at all points along a stream, which in turn can be used to determine if a stream is intermittent or perennial according to the Idaho Administrative Code operational definition. The selected regression equations were applied to create continuous grids of 7Q2 estimates for the eight low-flow regression regions of Idaho. By applying the 0.1 ft3/s criterion, the perennial streams have been estimated in each low-flow region. Uncertainty in the estimates is shown by identifying a 'transitional' zone, corresponding to flow estimates of 0.1 ft3/s plus and minus one standard error. Considerable additional uncertainty exists in the model of perennial streams presented in this report. The regression models provide overall estimates based on general trends within each regression region. These models do not include local factors such as a large spring or a losing reach that may greatly affect flows at any given point. Site-specific flow data, assuming a sufficient period of

  12. Bioenergy production from roadside grass

    DEFF Research Database (Denmark)

    Meyer, Ane Katharina Paarup; Ehimen, Ehiazesebhor Augustine; Holm-Nielsen, Jens Bo

    2014-01-01

    This paper presents a study of the feasibility of utilising roadside vegetation for biogas production in Denmark. The potential biomass yield, methane yields, and the energy balances of using roadside grass for biogas production was investigated based on spatial analysis. The results show...

  13. Growth responses, biomass partitioning, and nitrogen isotopes of prairie legumes in response to elevated temperature and varying nitrogen source in a growth chamber experiment.

    Science.gov (United States)

    Whittington, Heather R; Deede, Laura; Powers, Jennifer S

    2012-05-01

    Because legumes can add nitrogen (N) to ecosystems through symbiotic fixation, they play important roles in many plant communities, such as prairies and grasslands. However, very little research has examined the effect of projected climate change on legume growth and function. Our goal was to study the effects of temperature on growth, nodulation, and N chemistry of prairie legumes and determine whether these effects are mediated by source of N. We grew seedlings of Amorpha canescens, Dalea purpurea, Lespedeza capitata, and Lupinus perennis at 25/20°C (day/night) or 28/23°C with and without rhizobia and mineral N in controlled-environment growth chambers. Biomass, leaf area, nodule number and mass, and shoot N concentration and δ(15)N values were measured after 12 wk of growth. Both temperature and N-source affected responses in a species-specific manner. Lespedeza showed increased growth and higher shoot N content at 28°C. Lupinus showed decreases in nodulation and lower shoot N concentration at 28°C. The effect of temperature on shoot N concentration occurred only in individuals whose sole N source was N(2)-fixation, but there was no effect of temperature on δ(15)N values in these plants. Elevated temperature enhanced seedling growth of some species, while inhibiting nodulation in another. Temperature-induced shifts in legume composition or nitrogen dynamics may be another potential mechanism through which climate change affects unmanaged ecosystems.

  14. Global warming and prairie wetlands: potential consequences for waterfowl habitat

    Science.gov (United States)

    Poiani, Karen A.; Johnson, W. Carter

    1991-01-01

    The accumulation of greenhouse gasses in the atmosphere is expected to warm the earth's climate at an unprecedented rate (Ramanathan 1988, Schneider 1989). If the climate models are correct, within 100 years the earth will not only be warmer than it has been during the past million years, but the change will have occurred more rapidly than any on record. Many profound changes in the earth's environment are expected, including rising sea level, increasing aridity in continental interiors, and melting permafrost. Ecosystems are expected to respond variously to a rapidly changing climate. Tree ranges in eastern North American are expected to shift northward, and seed dispersal may not be adequate to maintain current diversity (Cohn 1989, Johnson and Webb 1989). In coastal wetlands, rising sea level from melting icecaps and thermal expansion could flood salt-grass marshes and generally reduce the size and productivity of the intertidal zone (Peters and Darling 1985). As yet, little attention has been given to the possible effects of climatic warming on inland prairie wetland ecosystems. These wetlands, located in the glaciated portion of the North American Great Plains (Figure 1), constitute the single most important breeding area for waterfowl on this continent (Hubbard 1988). This region annually produces 50-80% of the continent's total duck production (Batt et al. 1989). These marshes also support a variety of other wildlife, including many species of nongame birds, muskrat, and mink (Kantrud et al. 1989a). Prairie wetlands are relatively shallow, water-holding depressions that vary in size, water permanence, and water chemistry. Permanence types include temporary ponds (typically holding water for a few weeks in the springs), seasonal ponds (holding water from spring until early summer), semipermanent ponds (holding water throughout the growing season during most years), and large permanent lakes (Stewart and Kantrud 1971). Refilling usually occurs in spring from

  15. Nutrient removal by prairie filter strips in agricultural landscapes

    Science.gov (United States)

    X. Zhou; M.J. Helmers; H. Asbjornsen; R. Kolka; M.D. Tomer; R.M. Cruse

    2014-01-01

    Nitrogen (N) and phosphorus (P) from agricultural landscapes have been identified as primary sources of excess nutrients in aquatic systems. The main objective of this study was to evaluate the effectiveness of prairie filter strips (PFS) in removing nutrients from cropland runoff in 12 small watersheds in central Iowa. Four treatments with PFS of different spatial...

  16. Resistance to plague among black-tailed prairie dog populations

    Science.gov (United States)

    Rocke, Tonie E.; Williamson, Judy; Cobble, Kacy R.; Busch, Joseph D.; Antolin, Michael F.; Wagner, David M.

    2012-01-01

    In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (pdogs were quite similar in their response, with overall survival rates of 50% and 60%, respectively. Prairie dogs from these states were heterogenous in their response, with some animals dying at the lowest dose (37% and 20%, respectively) and some surviving even at the highest dose (29% and 40%, respectively). Microsatellite analysis revealed that all three groups were distinct genetically, but further studies are needed to establish a genetic basis for the observed differences in plague resistance.

  17. Food habits of nesting prairie falcons in Campbell County

    Science.gov (United States)

    John R. Squires; Stanley H. Anderson; Robert Oakleaf

    1989-01-01

    Fifteen species of prey were utilized by nesting Prairie Falcons (Falco mexicanus) as determined through pellet analysis. Thirteen-lined Ground Squirrels (Spermophilus tridecemlineatus), the most common prey, were present in 91% of the pellets, followed by Western Meadowlarks (Sturnella neglecta) which were present in 56% of pellets. Horned Larks (Eremophila...

  18. Prairie Restoration Project: Alternatives for Identifying Gifted Students

    Science.gov (United States)

    Salisbury, Katie E.; Rule, Audrey C.; Vander Zanden, Sarah M.

    2016-01-01

    An authentic, challenging curriculum engaged middle school students from an urban district in exploratory work related to restoring a small prairie at the school. Integrated science-literacy-arts activities were coupled with a system of thinking skills that helped students view issues from different perspectives. Impassioned guest speakers and an…

  19. Overview of Prairie Planting Techniques and Maintenance Requirements

    Science.gov (United States)

    2007-02-01

    districts have these drills 6 ERDC TN-EMRRP-ER-05 February 2007 available for rent. A three-point broadcast seeder or a fertilizer spreader can...lengthens the growing season for prairie plants but shortens it for many weedy species (Pauly 1997). Fire allows for nutrient recycling in the ecosystem by

  20. Selected hydrologic data, Camas Prairie, south-central Idaho

    Science.gov (United States)

    Young, H.W.; Backsen, R.L.; Kenyon, K.S.

    1978-01-01

    This report presents data collected during a 1-year study of the water resources of Camas Prairie, Idaho. Included are records of wells, discharge measurements of streams, hydrographs of water levels in wells, water-quality data, and drillers ' logs of wells. The data are conveniently made available to supplement an interpretive report, which will be published separately. (Woodard-USGS)

  1. Camel spider (Solifugae) use of prairie dog colonies

    Science.gov (United States)

    Solifugids (camel spiders) are widespread throughout arid regions of western North America and are thought to be important in structuring desert arthropod communities. Despite the ubiquity of camel spiders, little is known about their ecology. Black-tailed prairie dogs (Cynomys ludovicianus) are als...

  2. Butterfly responses to prairie restoration through fire and grazing

    Science.gov (United States)

    Vogel, Jennifer A.; Debinski, Diane M.; Koford, Rolf R.; Miller, J.R.

    2007-01-01

    The development of land for modern agriculture has resulted in losses of native prairie habitat. The small, isolated patches of prairie habitat that remain are threatened by fire suppression, overgrazing, and invasion by non-native species. We evaluated the effects of three restoration practices (grazing only, burning only, and burning and grazing) on the vegetation characteristics and butterfly communities of remnant prairies. Total butterfly abundance was highest on prairies that were managed with burning and grazing and lowest on those that were only burned. Butterfly species richness did not differ among any of the restoration practices. Butterfly species diversity was highest on sites that were only burned. Responses of individual butterfly species to restoration practices were highly variable. In the best predictive regression model, total butterfly abundance was negatively associated with the percent cover of bare ground and positively associated with the percent cover of forbs. Canonical correspondence analysis revealed that sites with burned only and grazed only practices could be separated based on their butterfly community composition. Butterfly communities in each of the three restoration practices are equally species rich but different practices yield compositionally different butterfly communities. Because of this variation in butterfly species responses to different restoration practices, there is no single practice that will benefit all species or even all species within habitat-specialist or habitat-generalist habitat guilds. ?? 2007 Elsevier Ltd. All rights reserved.

  3. Recommended methods for range-wide monitoring of prairie dogs in the United States

    Science.gov (United States)

    McDonald, Lyman L.; Stanley, Thomas R.; Otis, David L.; Biggins, Dean E.; Stevens, Patricia D.; Koprowski, John L.; Ballard, Warren

    2011-01-01

    One of the greatest challenges for conserving grassland, prairie scrub, and shrub-steppe ecosystems is maintaining prairie dog populations across the landscape. Of the four species of prairie dogs found in the United States, the Utah prairie dog (Cynomys parvidens) is listed under the Endangered Species Act (ESA) as threatened, the Gunnison's prairie dog (C. gunnisoni) is a candidate for listing in a portion of its range, and the black-tailed prairie dog (C. ludovicianus) and white-tailed prairie dog (C. leucurus) have each been petitioned for listing at least once in recent history. Although the U.S. Fish and Wildlife Service (USFWS) determined listing is not warranted for either the black-tailed prairie dog or white-tailed prairie dog, the petitions and associated reviews demonstrated the need for the States to monitor and manage for self-sustaining populations. In response to these findings, a multi-State conservation effort was initiated for the nonlisted species which included the following proposed actions: (1) completing an assessment of each prairie dog species in each State, (2) developing a range-wide monitoring protocol for each species using a statistically valid sampling procedure that would allow comparable analyses across States, and (3) monitoring prairie dog status every 3-5 years depending upon the species. To date, each State has completed an assessment and currently is monitoring prairie dog status; however, for some species, the inconsistency in survey methodology has made it difficult to compare data year-to-year or State-to-State. At the Prairie Dog Conservation Team meeting held in November 2008, there was discussion regarding the use of different methods to survey prairie dogs. A recommendation from this meeting was to convene a panel in a workshop-type forum and have the panel review the different methods being used and provide recommendations for range-wide monitoring protocols for each species of prairie dog. Consequently, the Western

  4. Diets of swift foxes (Vulpes velox) in continuous and fragmented prairie in Northwestern Texas

    Science.gov (United States)

    Kamler, J.F.; Ballard, W.B.; Wallace, M.C.; Gipson, P.S.

    2007-01-01

    Distribution of the swift fox (Vulpes velox) has declined dramatically since the 1800s, and suggested causes of this decline are habitat fragmentation and transformation due to agricultural expansion. However, impacts of fragmentation and human-altered habitats on swift foxes still are not well understood. To better understand what effects these factors have on diets of swift foxes, scats were collected in northwestern Texas at two study sites, one of continuous native prairie and one representing fragmented native prairie interspersed with agricultural and fields in the Conservation Reserve Program. Leporids, a potential food source, were surveyed seasonally on both sites. Diets of swift foxes differed between sites; insects were consumed more on continuous prairie, whereas mammals, birds, and crops were consumed more on fragmented prairie. Size of populations of leporids were 2-3 times higher on fragmented prairie, and swift foxes responded by consuming more leporids on fragmented (11.1% frequency occurrence) than continuous (3.8%) prairie. Dietary diversity was greater on fragmented prairie during both years of the study. Differences in diets between sites suggested that the swift fox is an adaptable and opportunistic feeder, able to exploit a variety of food resources, probably in relation to availability of food. We suggest that compared to continuous native prairie, fragmented prairie can offer swift foxes a more diverse prey base, at least within the mosaic of native prairie, agricultural, and fields that are in the Conservation Reserve Program.

  5. Changing the energy climate: clean and green heat from grass biofuel pellets

    International Nuclear Information System (INIS)

    Jannasch, R.; Samson, R.; DeMaio, A.; Adams, T.; Ho Lem, C.

    2001-01-01

    Uncertain energy supplies and international agreements to reduce greenhouse gas (GHG) emissions have created unique opportunities for biofuel development. Pelleted fuels from warm season grasses such as switchgrass (Panicum virgatum) can be grown for $3-4/GigaJoule (GJ) with only minor emissions of CO 2 . Using close-coupled gasifer combustion technology, switchgrass fuel pellets emit 86%, 91%, 71% and 89% less CO 2 than electricity, heating oil, natural gas and propane, respectively. Every 100 ha of switchgrass converted into pellet form and used to displace fossil fuel for space-heating prevents the emission of 1000 tonnes of CO 2 . Heating an average Ontario house with a 90GJ heat demand costs $1213 with switchgrass pellets compared to $2234, $1664, $882 and $3251 with electricity, heating oil, natural gas and propane, respectively. An estimated 23.4 million acres of agricultural land in Canada could potentially be converted to perennial grass biofuel production. The depressed farm sector would benefit economically from energy farming. Low-grade heat energy derived from grass pellets could displace some of the 30,000 GigaWatt Hours of electricity currently used for home heating in Quebec, Ontario and Manitoba. Surplus electricity could be exported or used to replace nuclear or coal burning plants. Contrary to prevailing beliefs that reducing GHG emissions will raise societal energy costs, pelletized grass biofuels could provide consumers with less expensive and more GHG-friendly heating options than most fossil energy sources. If the political support and direction exist to implement the Kyoto Protocol as intended, grass pellets could well become a heating fuel of choice in North America. (author)

  6. Biomonitoring of airborne mercury with perennial ryegrass cultures

    International Nuclear Information System (INIS)

    Temmerman, Ludwig de; Claeys, Natacha; Roekens, Edward; Guns, Marc

    2007-01-01

    A biomonitoring network with grass cultures was established near a chlor-alkali plant and the mercury concentration in the cultures were compared with the average atmospheric total gaseous mercury (TGM). Biomonitoring techniques based on different exposure periods were carried out. When comparing the mercury concentration in the grass cultures, both the average atmospheric TGM concentration during exposure and the exposure time determined to a large extent the accumulation rate of TGM. The maximum tolerable level of mercury in grass (≅110 μg kg -1 DM) corresponds with an average TGM concentration of 11 ng m -3 for 28 days exposure. The background concentrations in grass were on an average 15 μg kg -1 DM and the effect detection limit (EDL) was 30 μg kg -1 DM. This value corresponds with an average TGM concentration of 3.2 and 4.2 ng m -3 for 28 and 14 days exposure, respectively, which is in turn the biological detection limit (BDL) of ambient TGM. Exposures for 7 days were less appropriate for biomonitoring. - Grass accumulates TGM as a function of the atmospheric concentration and exposure time

  7. Mapping the temporary and perennial character of whole river networks

    Science.gov (United States)

    González-Ferreras, A. M.; Barquín, J.

    2017-08-01

    Knowledge of the spatial distribution of temporary and perennial river channels in a whole catchment is important for effective integrated basin management and river biodiversity conservation. However, this information is usually not available or is incomplete. In this study, we present a statistically based methodology to classify river segments from a whole river network (Deva-Cares catchment, Northern Spain) as temporary or perennial. This method is based on an a priori classification of a subset of river segments as temporary or perennial, using field surveys and aerial images, and then running Random Forest models to predict classification membership for the rest of the river network. The independent variables and the river network were derived following a computer-based geospatial simulation of riverine landscapes. The model results show high values of overall accuracy, sensitivity, and specificity for the evaluation of the fitted model to the training and testing data set (≥0.9). The most important independent variables were catchment area, area occupied by broadleaf forest, minimum monthly precipitation in August, and average catchment elevation. The final map shows 7525 temporary river segments (1012.5 km) and 3731 perennial river segments (662.5 km). A subsequent validation of the mapping results using River Habitat Survey data and expert knowledge supported the validity of the proposed maps. We conclude that the proposed methodology is a valid method for mapping the limits of flow permanence that could substantially increase our understanding of the spatial links between terrestrial and aquatic interfaces, improving the research, management, and conservation of river biodiversity and functioning.

  8. A new emphasis on root traits for perennial grass and legume varieties with environmental and ecological benefits.

    Science.gov (United States)

    Marshall, Athole H; Collins, Rosemary P; Humphreys, Mike W; Scullion, John

    2016-02-01

    Grasslands cover a significant proportion of the agricultural land within the UK and across the EU, providing a relatively cheap source of feed for ruminants and supporting the production of meat, wool and milk from grazing animals. Delivering efficient animal production from grassland systems has traditionally been the primary focus of grassland-based research. But there is increasing recognition of the ecological and environmental benefits of these grassland systems and the importance of the interaction between their component plants and a host of other biological organisms in the soil and in adjoining habitats. Many of the ecological and environmental benefits provided by grasslands emanate from the interactions between the roots of plant species and the soil in which they grow. We review current knowledge on the role of grassland ecosystems in delivering ecological and environmental benefits. We will consider how improved grassland can deliver these benefits, and the potential opportunities for plant breeding to improve specific traits that will enhance these benefits whilst maintaining forage production for livestock consumption. Opportunities for exploiting new plant breeding approaches, including high throughput phenotyping, and for introducing traits from closely related species are discussed.

  9. Methods for suspension culture, protoplast extraction, and transformation of high-biomass yielding perennial grass Arundo donax.

    Science.gov (United States)

    Pigna, Gaia; Dhillon, Taniya; Dlugosz, Elizabeth M; Yuan, Joshua S; Gorman, Connor; Morandini, Piero; Lenaghan, Scott C; Stewart, C Neal

    2016-12-01

    Arundo donax L. is a promising biofuel feedstock in the Mediterranean region. Despite considerable interest in its genetic improvement, Arundo tissue culture and transformation remains arduous. The authors developed methodologies for cell- and tissue culture and genetic engineering in Arundo. A media screen was conducted, and a suspension culture was established using callus induced from stem axillary bud explants. DBAP medium, containing 9 µM 2,4-D and 4.4 µM BAP, was found to be the most effective medium among those tested for inducing cell suspension cultures, which resulted in a five-fold increase in tissue mass over 14 days. In contrast, CIM medium containing 13 µM 2,4-D, resulted in just a 1.4-fold increase in mass over the same period. Optimized suspension cultures were superior to previously-described solidified medium-based callus culture methods for tissue mass increase. Suspension cultures proved to be very effective for subsequent protoplast isolation. Protoplast electroporation resulted in a 3.3 ± 1.5% transformation efficiency. A dual fluorescent reporter gene vector enabled the direct comparison of the CAMV 35S promoter with the switchgrass ubi2 promoter in single cells of Arundo. The switchgrass ubi2 promoter resulted in noticeably higher reporter gene expression compared with that conferred by the 35S promoter in Arundo. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Development of SSR Markers Based on Transcriptome Sequencing and Association Analysis with Drought Tolerance in Perennial Grass Miscanthus from China

    Directory of Open Access Journals (Sweden)

    Gang Nie

    2017-05-01

    Full Text Available Drought has become a critical environmental stress affecting on plant in temperate area. As one of the promising bio-energy crops to sustainable biomass production, the genus Miscanthus has been widely studied around the world. However, the most widely used hybrid cultivar among this genus, Miscanthus × giganteus is proved poor drought tolerance compared to some parental species. Here we mainly focused on Miscanthus sinensis, which is one of the progenitors of M. × giganteus providing a comparable yield and well abiotic stress tolerance in some places. The main objectives were to characterize the physiological and photosynthetic respond to drought stress and to develop simple sequence repeats (SSRs markers associated with drought tolerance by transcriptome sequencing within an originally collection of 44 Miscanthus genotypes from southwest China. Significant phenotypic differences were observed among genotypes, and the average of leaf relative water content (RWC were severely affected by drought stress decreasing from 88.27 to 43.21%, which could well contribute to separating the drought resistant and drought sensitive genotype of Miscanthus. Furthermore, a total of 16,566 gene-associated SSRs markers were identified based on Illumina RNA sequencing under drought conditions, and 93 of them were randomly selected to validate. In total, 70 (75.3% SSRs were successfully amplified and the generated loci from 30 polymorphic SSRs were used to estimate the genetic differentiation and population structure. Finally, two optimum subgroups of the population were determined by structure analysis and based on association analysis, seven significant associations were identified including two markers with leaf RWC and five markers with photosynthetic traits. With the rich sequencing resources annotation, such associations would serve an efficient tool for Miscanthus drought response mechanism study and facilitate genetic improvement of drought resistant for this species.

  11. Arid oil-field restoration: native perennial grasses suppress weeds and erosion, but also suppress native shrubs

    Science.gov (United States)

    1. Long-lived, drought-tolerant shrubs are dominant components of many arid ecosystems, and shrubs provide multiple ecosystem services (e.g., soil stabilization, herbaceous plant facilitation, carbon storage and wildlife habitat). On denuded sites, shrub restoration is hindered by abiotic (erosion ...

  12. A transcriptome map of perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Studer Bruno

    2012-04-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are increasingly becoming the DNA marker system of choice due to their prevalence in the genome and their ability to be used in highly multiplexed genotyping assays. Although needed in high numbers for genome-wide marker profiles and genomics-assisted breeding, a surprisingly low number of validated SNPs are currently available for perennial ryegrass. Results A perennial ryegrass unigene set representing 9,399 genes was used as a reference for the assembly of 802,156 high quality reads generated by 454 transcriptome sequencing and for in silico SNP discovery. Out of more than 15,433 SNPs in 1,778 unigenes fulfilling highly stringent assembly and detection parameters, a total of 768 SNP markers were selected for GoldenGate genotyping in 184 individuals of the perennial ryegrass mapping population VrnA, a population being previously evaluated for important agronomic traits. A total of 592 (77% of the SNPs tested were successfully called with a cluster separation above 0.9. Of these, 509 (86% genic SNP markers segregated in the VrnA mapping population, out of which 495 were assigned to map positions. The genetic linkage map presented here comprises a total of 838 DNA markers (767 gene-derived markers and spans 750 centi Mogan (cM with an average marker interval distance of less than 0.9 cM. Moreover, it locates 732 expressed genes involved in a broad range of molecular functions of different biological processes in the perennial ryegrass genome. Conclusions Here, we present an efficient approach of using next generation sequencing (NGS data for SNP discovery, and the successful design of a 768-plex Illumina GoldenGate genotyping assay in a complex genome. The ryegrass SNPs along with the corresponding transcribed sequences represent a milestone in the establishment of genetic and genomics resources available for this species and constitute a further step towards molecular breeding

  13. Avoidance behavior by prairie grouse: implications for development of wind energy.

    Science.gov (United States)

    Pruett, Christin L; Patten, Michael A; Wolfe, Donald H

    2009-10-01

    New wind-energy facilities and their associated power transmission lines and roads are being constructed at a rapid pace in the Great Plains of North America. Nevertheless, little is known about the possible negative effects these anthropogenic features might have on prairie birds, one of the most threatened groups in North America. We examined radiotelemetry tracking locations of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) and Greater Prairie-Chickens (T. cupido) in two locations in Oklahoma to determine whether these birds avoided or changed movement behavior near power lines and paved highways. We tracked 463 Lesser Prairie-Chickens (15,071 tracking locations) and 216 Greater Prairie-Chickens (5,750 locations) for 7 and 3 years, respectively. Individuals of both species avoided power lines by at least 100 m and Lesser Prairie-Chickens avoided one of the two highways by 100 m. Prairie-chickens crossed power lines less often than expected if birds moved randomly (p 0.05). In addition, home ranges of Lesser Prairie-Chickens overlapped the power line less often than would be expected by chance placement of home ranges; this result was supported by kernel-density estimation of home ranges. It is likely that new power lines (and other tall structures such as wind turbines) will lead to avoidance of previously suitable habitat and will serve as barriers to movement. These two factors will likely increase fragmentation in an already fragmented landscape if wind energy development continues in prairie habitats.

  14. One hundred and six years of population and community dynamics of Sonoran Desert Laboratory perennials

    Science.gov (United States)

    Rodriguez-Buritica, Susana; Raichle, Helen; Webb, Robert H.; Turner, Raymond M.; Venable, Larry

    2013-01-01

    This data set constitutes all information associated with the Spalding-Shreve permanent vegetation plots from 1906 through 2012, which is the longest-running plant monitoring program in the world. The program consists of detailed maps of all Sonoran Desert perennial plants in 30 permanent plots located on Tumamoc Hill, near Tucson, Arizona, USA. Most of these plots are 10 m × 10 m quadrats that were established by Volney Spalding and Forrest Shreve between 1906 and 1928. Analyses derived from these data have been pivotal in testing early theories on plant community succession, plant life history traits, plant longevity, and population dynamics. One of the major contributions of this data set is the species-specific demographic traits that derived from estimating individual plant trajectories for more than 106 years. Further use of these data might shed light on spatially explicit population and community dynamics, as well as long-term changes attributable to global change. Data presented here consist of digital versions of original maps created between 1906 and 1984 and digital data from recent censuses between 1993 and 2012. Attributes associated with these maps include location and coverage of all shrubs, and in some cases, plant height. In addition, we present plot-specific summaries of plant cover and density for each census year and all other information collected, including seedling counts, grass coverage, and annual species enumerations. We reference the repeat photography of these plots, which began in 1906; these images are stored at the Desert Laboratory Collection of Repeat Photography in Tucson. Initial data collection consisted of grid-mapping the plots manually on graph paper; starting in 1993, Total Stations (which allow a direct digitalization, and more accurate mapping) were used to survey root crowns and canopies.

  15. Soil denitrifier community size changes with land use change to perennial bioenergy cropping systems

    Science.gov (United States)

    Thompson, Karen A.; Deen, Bill; Dunfield, Kari E.

    2016-10-01

    Dedicated biomass crops are required for future bioenergy production. However, the effects of large-scale land use change (LUC) from traditional annual crops, such as corn-soybean rotations to the perennial grasses (PGs) switchgrass and miscanthus, on soil microbial community functioning is largely unknown. Specifically, ecologically significant denitrifying communities, which regulate N2O production and consumption in soils, may respond differently to LUC due to differences in carbon (C) and nitrogen (N) inputs between crop types and management systems. Our objective was to quantify bacterial denitrifying gene abundances as influenced by corn-soybean crop production compared to PG biomass production. A field trial was established in 2008 at the Elora Research Station in Ontario, Canada (n  =  30), with miscanthus and switchgrass grown alongside corn-soybean rotations at different N rates (0 and 160 kg N ha-1) and biomass harvest dates within PG plots. Soil was collected on four dates from 2011 to 2012 and quantitative PCR was used to enumerate the total bacterial community (16S rRNA) and communities of bacterial denitrifiers by targeting nitrite reductase (nirS) and N2O reductase (nosZ) genes. Miscanthus produced significantly larger yields and supported larger nosZ denitrifying communities than corn-soybean rotations regardless of management, indicating large-scale LUC from corn-soybean to miscanthus may be suitable in variable Ontario climatic conditions and under varied management, while potentially mitigating soil N2O emissions. Harvesting switchgrass in the spring decreased yields in N-fertilized plots, but did not affect gene abundances. Standing miscanthus overwinter resulted in higher 16S rRNA and nirS gene copies than in fall-harvested crops. However, the size of the total (16S rRNA) and denitrifying bacterial communities changed differently over time and in response to LUC, indicating varying controls on these communities.

  16. Checklist of Serengeti Ecosystem Grasses

    Science.gov (United States)

    Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    Abstract We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution. PMID:27226761

  17. Checklist of Serengeti Ecosystem Grasses.

    Science.gov (United States)

    Williams, Emma Victoria; Elia Ntandu, John; Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution.

  18. On the ecological genetics of the clonal perennial Agrostis stolonifera

    NARCIS (Netherlands)

    Kik, Christoffel

    1987-01-01

    There have to date been few studies specifically addressed to the evolution of clonal organisms. The present study attempts to fill this gap and aims to analyse the distribution pattern of a clonal plant species, using the wide-spread grass Agrostis stolonifera L.(Creeping Bent) as a model species.

  19. COLONIZATION AND DIFFERENTIATION IN THE CLONAL PERENNIAL AGROSTIS-STOLONIFERA

    NARCIS (Netherlands)

    Kik, C; van Andel, Jelte; van Delden, Wilke; Joenje, W; Bijlsma, Rudolf

    1990-01-01

    (1) Colonization and differentiation were studied in four populations (inland meadow, salt-marsh, polder and sand-dune) of the widespread grass Agrostis stolonifera. A common-garden experiment showed that the overall population variability could be divided, through the use of principal component

  20. Climate impacts on the agribusiness sectors of a prairie economy

    International Nuclear Information System (INIS)

    Arthur, L.M.; Kooten, G.C. Van.

    1992-01-01

    Global warming is likely to result in increased agricultural output on the Canadian prairies. However, using input-output analysis, it is shown that the potential impact of global warming on agribusiness, while significant, is both uncertain and relatively small compared to the impact of government agricultural policies pertaining to the grain and livestock sectors. Furthermore, caution is required in deciding whether or not western Canada and prairie agribusinesses are net beneficiaries of a greenhouse effect because climate-induced changes in agricultural output elsewhere in the world still need to be taken into account. Most previous studies on American and European agriculture under the greenhouse effect predict reduced yields of current crops, which could mean improved markets for Canadian crops. 27 refs., 4 figs., 2 tabs

  1. Prairie rattlesnake envenomation in 27 New World camelids.

    Science.gov (United States)

    Sonis, J M; Hackett, E S; Callan, R J; Holt, T N; Hackett, T B

    2013-01-01

    Morbidity and case fatality from rattlesnake envenomation is regionally specific because of variability in relative toxicity of the species of snake encountered. A previous report of rattlesnake envenomation in New World camelids (NWC) from the western coastal United States documented high case fatality rates and guarded prognosis for survival. To describe clinical findings, treatments, and outcome of NWC with prairie rattlesnake (Crotalus viridis viridis) envenomation in the Rocky Mountain region of the United States. Twenty-seven NWC admitted to the Colorado State University Veterinary Teaching Hospital for evaluation of acute rattlesnake envenomation between 1992 and 2012. Medical records of NWC evaluated for rattlesnake envenomation as coded by the attending clinician and identified by a database search were reviewed retrospectively. Month of admission, signalment, area of bite, clinical and clinicopathologic data, treatments, and outcome were recorded. Twenty-five llamas and 2 alpacas were admitted for envenomation. Llamas were overrepresented compared to hospital caseload. The face was the most common site of envenomation, observed in 96% of recorded cases. Presenting clinical signs included fever, tachypnea, tachycardia, and respiratory distress. Nine animals required a tracheotomy. Median hospitalization time was 3 days and overall survival rate was 69%. Case fatality rate for prairie rattlesnake envenomation in NWC was lower than that reported in the Western coastal region of the United States and similar to that reported for prairie rattlesnake envenomation in horses. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  2. Resting state brain networks in the prairie vole.

    Science.gov (United States)

    Ortiz, Juan J; Portillo, Wendy; Paredes, Raul G; Young, Larry J; Alcauter, Sarael

    2018-01-19

    Resting state functional magnetic resonance imaging (rsfMRI) has shown the hierarchical organization of the human brain into large-scale complex networks, referred as resting state networks. This technique has turned into a promising translational research tool after the finding of similar resting state networks in non-human primates, rodents and other animal models of great value for neuroscience. Here, we demonstrate and characterize the presence of resting states networks in Microtus ochrogaster, the prairie vole, an extraordinary animal model to study complex human-like social behavior, with potential implications for the research of normal social development, addiction and neuropsychiatric disorders. Independent component analysis of rsfMRI data from isoflurane-anestethized prairie voles resulted in cortical and subcortical networks, including primary motor and sensory networks, but also included putative salience and default mode networks. We further discuss how future research could help to close the gap between the properties of the large scale functional organization and the underlying neurobiology of several aspects of social cognition. These results contribute to the evidence of preserved resting state brain networks across species and provide the foundations to explore the use of rsfMRI in the prairie vole for basic and translational research.

  3. Energizing marginal soils: A perennial cropping system for Sida hermaphrodita

    Science.gov (United States)

    Nabel, Moritz; Poorter, Hendrik; Temperton, Vicky; Schrey, Silvia D.; Koller, Robert; Schurr, Ulrich; Jablonowski, Nicolai D.

    2017-04-01

    As a way to avoid land use conflicts, the use of marginal soils for the production of plant biomass can be a sustainable alternative to conventional biomass production (e.g. maize). However, new cropping strategies have to be found that meet the challenge of crop production under marginal soil conditions. We aim for increased soil fertility by the use of the perennial crop Sida hermaphrodita in combination with organic fertilization and legume intercropping to produce substantial biomass yield. We present results of a three-year outdoor mesocosm experiment testing the perennial energy crop Sida hermaphrodita grown on a marginal model substrate (sand) with four kinds of fertilization (Digestate broadcast, Digestate Depot, mineral NPK and unfertilized control) in combination with legume intercropping. After three years, organic fertilization (via biogas digestate) compared to mineral fertilization (NPK), reduced the nitrate concentration in leachate and increased the soil carbon content. Biomass yields of Sida were 25% higher when fertilized organically, compared to mineral fertilizer. In general, digestate broadcast application reduced root growth and the wettability of the sandy substrate. However, when digestate was applied locally as depot to the rhizosphere, root growth increased and the wettability of the sandy substrate was preserved. Depot fertilization increased biomass yield by 10% compared to digestate broadcast fertilization. We intercropped Sida with various legumes (Trifolium repens, Trifolium pratense, Melilotus spp. and Medicago sativa) to enable biological nitrogen fixation and make the cropping system independent from synthetically produced fertilizers. We could show that Medicago sativa grown on marginal substrate fixed large amounts of N, especially when fertilized organically, whereas mineral fertilization suppressed biological nitrogen fixation. We conclude that the perennial energy crop Sida in combination with organic fertilization has great

  4. Evaluation of Seed and Forage Yield of Perennial Plants with Low Water Requirement in Abandoned Farming Lands

    Directory of Open Access Journals (Sweden)

    Ali gazanchian

    2017-10-01

    Full Text Available Introduction Drought is a natural phenomenon in arid and semi-arid regions of the world. It is created by low precipitation, high evaporation and reduced soil moisture. Today, they are the major threats to agricultural lands due to fluctuations in rainfall, limited water resources, wells salinization and subsequently abandoned farming lands. Iran is located on the world's dry belt and more than 90 percent of its area is located in the arid and semi-arid climatic regions. It has been reported that the annual rate of soil erosion is up to 33 tons per hectare and 5 to 6 times more than the standard limit. Also, 90% of the country's protein production comes from animals sources. Due to the lack of adequate forage production, the main burden of protein production is imposed on the natural resources and pastures. Therefore, In order to enhance soil stabilization and maintain its fertility, optimum use of off-season precipitations, preventing the flow of water and protecting the abandoned farming lands from the flood risk, increasing the water permeability in the soil, and helping to feed the underwater aquifers and finally the production of forage and seeds, the development of perennial plants cultivation is an important conservative practice. The aim of this study is to emphasize on the selection of the best perennial forage species with low water requirements and acceptable performance for renovation of the abandoned farming lands and moving towards sustainable agriculture approaches. Materials and Methods In this experiment, 10 species of perennial grasses (Agropyron elongatum Host., Secale montanum Guss., Festuca arundinaceae Schreb., Dactylis glomerata L., Agropyron intermedium Host., Agropyron repense L., Agropyron cristatum L., Panicum antidutale Retz., Bromus inermis Leyss., Bromus riparius Rehmann, Agropyron cristatum L. and two legumes includes Trifolium pratense L., Onobrychis sativa Lam. were studied at Asatan-e-Ghods Razavi farm in

  5. Enhancing GRASS data communication with videographic technology

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, R.G. [Argonne National Lab., IL (United States); Gerdes, D.; Youngs, D. [Army Construction Engineering Research Lab., Champaign, IL (United States)

    1992-07-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  6. Enhancing GRASS data communication with videographic technology

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, R.G. (Argonne National Lab., IL (United States)); Gerdes, D.; Youngs, D. (Army Construction Engineering Research Lab., Champaign, IL (United States))

    1992-01-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  7. Thermogravimetric analysis of forest understory grasses

    Science.gov (United States)

    Thomas Elder; John S. Kush; Sharon M. Hermann

    2011-01-01

    Forest understory grasses are of significance in the initiation, establishment and maintenance of fire, whether used as a management tool or when occurring as wildfire. The fundamental thermal properties of such grasses are critical to their behavior in fire situations and have been investigated in the current work by the application of thermogravimetric analysis (TGA...

  8. Tuberculosis transmission in the Indigenous peoples of the Canadian prairies.

    Science.gov (United States)

    Patel, Smit; Paulsen, Catherine; Heffernan, Courtney; Saunders, Duncan; Sharma, Meenu; King, Malcolm; Hoeppner, Vernon; Orr, Pamela; Kunimoto, Dennis; Menzies, Dick; Christianson, Sara; Wolfe, Joyce; Boffa, Jody; McMullin, Kathleen; Lopez-Hille, Carmen; Senthilselvan, Ambikaipakan; Long, Richard

    2017-01-01

    The prairie provinces of Canada. To characterize tuberculosis (TB) transmission among the Indigenous and non-Indigenous Canadian-born peoples of the prairie provinces of Canada. A prospective epidemiologic study of consecutively diagnosed adult (age ≥ 14 years) Canadian-born culture-positive pulmonary TB cases on the prairies, hereafter termed "potential transmitters," and the transmission events generated by them. "Transmission events" included new positive tuberculin skin tests (TSTs), TST conversions, and secondary cases among contacts. In the years 2007 and 2008, 222 potential transmitters were diagnosed on the prairies. Of these, the vast majority (198; 89.2%) were Indigenous peoples who resided in either an Indigenous community (135; 68.2%) or a major metropolitan area (44; 22.2%). Over the 4.5-year period between July 1st, 2006 and December 31st 2010, 1085 transmission events occurred in connection with these potential transmitters. Most of these transmission events were attributable to potential transmitters who identified as Indigenous (94.5%). With a few notable exceptions most transmitters and their infected contacts resided in the same community type. In multivariate models positive smear status and a higher number of close contacts were associated with increased transmission; adjusted odds ratios (ORs) and 95% confidence intervals (CIs), 4.30 [1.88, 9.84] and 2.88 [1.31, 6.34], respectively. Among infected contacts, being Indigenous was associated with disease progression; OR and 95% CI, 3.59 [1.27, 10.14] and 6.89 [2.04, 23.25] depending upon Indigenous group, while being an infected casual contact was less likely than being a close contact to be associated with disease progression, 0.66 [0.44, 1.00]. In the prairie provinces of Canada and among Canadian-born persons, Indigenous peoples account for the vast majority of cases with the potential to transmit as well as the vast majority of infected contacts. Active case finding and preventative therapy

  9. SQ grass sublingual allergy immunotherapy tablet for disease-modifying treatment of grass pollen allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Dahl, Ronald; Roberts, Graham; de Blic, Jacques

    2016-01-01

    BACKGROUND: Allergy immunotherapy is a treatment option for allergic rhinoconjunctivitis (ARC). It is unique compared with pharmacotherapy in that it modifies the immunologic pathways that elicit an allergic response. The SQ Timothy grass sublingual immunotherapy (SLIT) tablet is approved in North...... America and throughout Europe for the treatment of adults and children (≥5 years old) with grass pollen-induced ARC. OBJECTIVE: The clinical evidence for the use of SQ grass SLIT-tablet as a disease-modifying treatment for grass pollen ARC is discussed in this review. METHODS: The review included...... the suitability of SQ grass SLIT-tablet for patients with clinically relevant symptoms to multiple Pooideae grass species, single-season efficacy, safety, adherence, coseasonal initiation, and cost-effectiveness. The data from the long-term SQ grass SLIT-tablet clinical trial that evaluated a clinical effect 2...

  10. Tradeoffs between water requirements and yield stability in annual vs. perennial crops

    Science.gov (United States)

    Vico, Giulia; Brunsell, Nathaniel A.

    2018-02-01

    Population growth and changes in climate and diets will likely further increase the pressure on agriculture and water resources globally. Currently, staple crops are obtained from annuals plants. A shift towards perennial crops may enhance many ecosystem services, but at the cost of higher water requirements and lower yields. It is still unclear when the advantages of perennial crops overcome their disadvantages and perennial crops are thus a sustainable solution. Here we combine a probabilistic description of the soil water balance and crop development with an extensive dataset of traits of congeneric annuals and perennials to identify the conditions for which perennial crops are more viable than annual ones with reference to yield, yield stability, and effective use of water. We show that the larger and more developed roots of perennial crops allow a better exploitation of soil water resources and a reduction of yield variability with respect to annual species, but their yields remain lower when considering grain crops. Furthermore, perennial crops have higher and more variable irrigation requirements and lower water productivity. These results are important to understand the potential consequences for yield, its stability, and water resource use of a shift from annual to perennial crops and, more generally, if perennial crops may be more resilient than annual crops in the face of climatic fluctuations.

  11. Effects of Seasonal and Perennial Grazing on Soil Fauna Community and Microbial Biomass Carbon in the Subalpine Meadows of Yunnan, Southwest China

    Institute of Scientific and Technical Information of China (English)

    LIU Shengjie; YANG Xiaodong; Anthony R.IVES; FENG Zhili; SHA Liqing

    2017-01-01

    Grazing and over-grazing may drive changes in the diversity and functioning of below-ground meadow ecosystems.A field soil survey was conducted to compare microbial biomass carbon (Cmin) and soil fauna communities in the two main grassland management systems in subalpine regions of Yunnan Province,China:perennial grazing currently practiced due to increasing herd sizes and traditional seasonal grazing.A three-year exclosure experiment was then conducted to further compare the effects of different grazing practices,including treatments of no mowing,perennial grazing (NM + G),mowing followed by seasonal grazing (M + G),mowing and no grazing (M + NG),and no mowing or grazing (NM + NG).The comparative survey result revealed that Cmin and total density of soil fauna were significantly lower at a perennially grazed site than at a seasonally grazed site.The experiment results showed that in comparison to non-grazing treatments (M + NG and NM + NG),grazing (NM + G and M + G) reduced total fauna density (by 150 individuals m-2) and the number of taxonomic groups present (by 0.32 taxa m-2).Mowing decreased Cmin (by 0.31 mg g-1).Furthermore,the NM + G treatment (perennial grazing) had the lowest density of Collembola (16.24 individuals m-2),one of the two most common taxonomic groups,although other taxonomic groups responded differently to the treatments.Treatment effects on soil fauna were consistent with those on above-ground grasses,in which C:N ratios were greatly reduced by grazing,with this effect being the greatest for the NM + G treatment.In contrast,different grazing treatments had little effect on C:N ratio of soil.Furthermore,the traditional grazing method (mowing followed by seasonal grazing) may have less severe effects on some taxonomic groups than perennial grazing.Therefore,an appropriate management should aim to protect soil fauna and microbes in this area from over-grazing and against further degradation.

  12. Heavy metal concentration in forage grasses and extractability from some acid mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.W.; Ibeabuchi, I.O.; Sistani, K.R.; Shuford, J.W. (Alabama A and M University, Normal (United States). Department of Plant and Soil Science)

    1993-06-01

    Laboratory and greenhouse studies were conducted on several forage grasses, bermudagrass ([ital Cynodon dactylon]), creeping red fescue ([ital Festuca rubra]), Kentucky 31-tall fescue ([ital Festuca arundinacea]), oat ([ital Avena sativa]), orchardgrass ([ital Dactylis glomerata]), perennial ryegrass ([ital Lolium perenne]), sorghum ([ital Sorghum bicolor]), triticale (X. [ital triticosecale Wittmack]), and winter wheat ([ital Triticum aestivum]) grown on three Alabama acid mine spoils to study heavy metal accumulation, dry matter yield and spoil metal extractability by three chemical extractants (Mehlich 1, DTPA, and 0.1 M HCl). Heavy metals removed by these extractants were correlated with their accumulation by several forage grasses. Among the forages tested, creeping red fescue did not survive the stressful conditions of any of the spoils, while orchard grass and Kentucky 31-tall fescue did not grow in Mulberry spoil. Sorghum followed by bermudagrass generally produced the highest dry matter yield. However, the high yielding bermudagrass was most effective in accumulating high tissue levels of Mn and Zn from all spoils (compared to the other grasses) but did not remove Ni. On the average, higher levels of metals were extracted from spoils in the order of 0.1 M HCl[gt] Mehlich 1[gt] DTPA. However, DTPA extracted all the metals from spoils while Mehlich 1 did not extract Pb and 0.1 M HCl did not extract detectable levels of Ni. All of the extractants were quite effective in determining plant available Zn from the spoils. For the other metals, the effective determination of plant availability depended on the crop, the extractant, and the metal in concert. 20 refs., 6 tabs.

  13. A HYPOTHESIS: COULD PORTABLE NATURAL GRASS BE A RISK FACTOR FOR KNEE INJURIES?

    Directory of Open Access Journals (Sweden)

    John Orchard

    2008-03-01

    Full Text Available Previous study has shown a likely link between increased shoe- surface traction and risk of knee Anterior Cruciate Ligament (ACL injury. Portable natural grass systems are being used more often in sport, but no study to date has investigated their relative safety. By their nature, they must have high resistance to falling apart and therefore newly laid systems may be at risk of creating excessive shoe-surface traction. This study describes two clusters of knee injuries (particularly non-contact ACL injuries, each occurring to players of one professional football team at single venue, using portable grass, in a short space of time. The first series included two ACL injuries, one posterolateral complex disruption and one lateral ligament tear occurring in two rugby league games on a portable bermudagrass surface in Brisbane, Australia. The second series included four non-contact ACL injuries over a period of ten weeks in professional soccer games on a portable Kentucky bluegrass/perennial ryegrass surface in Barcelona, Spain. Possible intrinsic risk factors are discussed but there was no common risk shared by the players. Although no measures of traction were made at the Brisbane venue, average rotational traction was measured towards the end of the injury cluster at Camp Nou, Barcelona, to be 48 Nm. Chance undoubtedly had a part to play in these clusters, but the only obvious common risk factor was play on a portable natural grass surface soon after it was laid. Further study is required to determine whether portable natural grass systems may exhibit high shoe-surface traction soon after being laid and whether this could be a risk factor for knee injury

  14. 77 FR 24975 - Endangered and Threatened Wildlife and Plants; Revised Recovery Plan for the Utah Prairie Dog

    Science.gov (United States)

    2012-04-26

    ...-FF06E00000] Endangered and Threatened Wildlife and Plants; Revised Recovery Plan for the Utah Prairie Dog... Utah prairie dog (Cynomys parvidens). This species is federally listed as threatened under the... recovery plan for the Utah prairie dog. The Service and other Federal agencies also will take these...

  15. 75 FR 57055 - Endangered and Threatened Wildlife and Plants; Draft Revised Recovery Plan for Utah Prairie Dog

    Science.gov (United States)

    2010-09-17

    ...] Endangered and Threatened Wildlife and Plants; Draft Revised Recovery Plan for Utah Prairie Dog AGENCY: Fish... recovery plan for the Utah prairie dog (Cynomys parvidens). This species is federally listed as threatened... and peer reviewers in an appendix to the approved recovery plan. The Utah prairie dog (Cynomys...

  16. 76 FR 31906 - Endangered and Threatened Wildlife and Plants; Revising the Special Rule for the Utah Prairie Dog

    Science.gov (United States)

    2011-06-02

    ... Special Rule for the Utah Prairie Dog AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule... prairie dog. We are proposing to revise the existing limits on take, and we also propose a new incidental... dogs see: http://www.fws.gov/mountain-prairie/species/mammals/UTprairiedog or http://ecos.fws.gov...

  17. 77 FR 46157 - Endangered and Threatened Wildlife and Plants; Revising the Special Rule for the Utah Prairie Dog

    Science.gov (United States)

    2012-08-02

    ... Utah Prairie Dog; Final Rule #0;#0;Federal Register / Vol. 77 , No. 149 / Thursday, August 2, 2012...-AW02 Endangered and Threatened Wildlife and Plants; Revising the Special Rule for the Utah Prairie Dog... special regulations for the conservation of the Utah prairie dog. We are revising our special regulations...

  18. 78 FR 26302 - Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken as a Threatened...

    Science.gov (United States)

    2013-05-06

    ...; 4500030113] RIN 1018-AY21 Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken... the lesser prairie-chicken (Tympanuchus pallidicinctus). In addition, we announce the reopening of the public comment period on the December 11, 2012, proposed rule to list the lesser prairie-chicken as a...

  19. 78 FR 75306 - Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken as a Threatened...

    Science.gov (United States)

    2013-12-11

    ...; 4500030113] RIN 1018-AY21 Endangered and Threatened Wildlife and Plants; Listing the Lesser Prairie-Chicken... the conservation of the lesser prairie-chicken (Tympanuchus pallidicinctus). In addition, we announce... prairie-chicken as a threatened species under the Act. We also announce the availability of the final...

  20. N transfer in three species grass-clover mixtures with chicory, ribwort plantain or caraway

    DEFF Research Database (Denmark)

    Dhamala, Nawa Raj; Rasmussen, Jim; Carlsson, Georg

    2017-01-01

    Background and aimsThere is substantial evidence that legume-derived Nitrogen (N) is transferred to neighboring non-legumes in grassland mixtures. However, there is sparse information about how deep rooted non-legume forage herbs (forbs) influence N transfer in multi-species grasslands. Methodology......Red clover (Trifolium pretense L.) was grown together with perennial ryegrass (Lolium perenne L.) and one of three forb species: chicory (Cichorium intybus L.), ribwort plantain (Plantago lanceolata L.) or caraway (Carum carvi L.) in a field experiment. During the first year after the establishment, red...... clover leaves were labeled with 15N-urea to determine the N transfer from red clover to companion ryegrass and forbs. ResultsOn an annual basis, up to 15 % of red clover N was transferred to the companion ryegrass and forbs, but predominantly to the grass. The forb species did not differ in their ability...

  1. Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie

    Science.gov (United States)

    Mac A. Callaham; Matt R. Whiles; John M. Blair

    2002-01-01

    In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...

  2. Ecology of fire in shortgrass prairie of the southern Great Plains

    Science.gov (United States)

    Paulette L. Ford; Guy R. McPherson

    1996-01-01

    The ecology of fire in shortgrass prairie of the southern Great Plains includes a complex interaction between the shortgrass prairie ecosystem and its inhabitants, all inextricably linked to land-use patterns. The history of the relationship between man and fire has been filled with ambivalence and mistrust, along with an appreciation of the power of fire as a...

  3. 77 FR 75119 - Dakota Prairie Grasslands, North Dakota; Oil and Gas Development Supplemental Environmental...

    Science.gov (United States)

    2012-12-19

    ... DEPARTMENT OF AGRICULTURE Forest Service Dakota Prairie Grasslands, North Dakota; Oil and Gas... to prepare a supplemental environmental impact statement. SUMMARY: In June of 2003, the Dakota... Dakota Prairie Grasslands Land and Resource Management Plan, based on the 2001 Northern Great Plains...

  4. The role of prairie dogs as a keystone species: response to Stapp

    Science.gov (United States)

    B. Miller; R. Reading; J. Hoogland; T. Clark; G. Ceballos; R. List; S. Forrest; L. Hanebury; P. Manzano; J. Pacheco; D. Uresk

    2000-01-01

    Stapp (1998) recently argued that it was premature to characterize prairie dogs (Cynomys spp.) as keystone species. In particular, Stapp directed much of his criticism at a paper some of us wrote (Miller et al. 1994). He mistakenly interprets the main objective of our paper as providing evidence that prairie dogs are keystone species. Rather, the...

  5. Review of black-tailed prairie dog reintroduction strategies and site selection: Arizona reintroduction

    Science.gov (United States)

    Sarah L. Hale; John L. Koprowski; Holly Hicks

    2013-01-01

    The black-tailed prairie dog (Cynomys ludovicianus) was once widely distributed throughout the western United States; however, anthropogenic influences have reduced the species’ numbers to 2 percent of historical populations. Black-tailed prairie dogs are described as a keystone species in the grassland ecosystem, and provide many unique services, including burrows for...

  6. Black-tailed prairie dog (Cynomys ludovicianus) response to seasonality and frequency of fire

    Science.gov (United States)

    Felicia D. Archuleta

    2014-01-01

    Fragmentation of the landscape, habitat loss, and fire suppression, all a result of European settlement and activities, have precipitated both the decline of Black-tailed prairie dog (Cynomys ludovicianus) populations and the occurrence of fire throughout the Great Plains, including the Shortgrass steppe of northeastern New Mexico. The presence of Black-tailed prairie...

  7. Prairie dog decline reduces the supply of ecosystem services and leads to desertification of semiarid grasslands.

    Directory of Open Access Journals (Sweden)

    Lourdes Martínez-Estévez

    Full Text Available Anthropogenic impacts on North American grasslands, a highly endangered ecosystem, have led to declines of prairie dogs, a keystone species, over 98% of their historical range. While impacts of this loss on maintenance of grassland biodiversity have been widely documented, much less is known about the consequences on the supply of ecosystem services. Here we assessed the effect of prairie dogs in the supply of five ecosystem services by comparing grasslands currently occupied by prairie dogs, grasslands devoid of prairie dogs, and areas that used to be occupied by prairie dogs that are currently dominated by mesquite scrub. Groundwater recharge, regulation of soil erosion, regulation of soil productive potential, soil carbon storage and forage availability were consistently quantitatively or qualitatively higher in prairie dog grasslands relative to grasslands or mesquite scrub. Our findings indicate a severe loss of ecosystem services associated to the absence of prairie dogs. These findings suggest that contrary to a much publicize perception, especially in the US, prairie dogs are fundamental in maintaining grasslands and their decline have strong negative impacts in human well - being through the loss of ecosystem services.

  8. Demography of black-tailed prairie dog populations reoccupying sites treated with rodenticide

    Science.gov (United States)

    R. P. Cincotta; Daniel W. Uresk; R. M. Hansen

    1987-01-01

    A rodenticide, zinc phosphide, was applied to remove black-tailed prairie dogs (Cynomys ludovicianus) from 6 haofa prairie dog colony in southwestern South Dakota. Another adjacent 6 ha was left untreated. The removal experiment was repeated two consecutive years. Contingency table analysis showed that the resultant population was not homogeneous;...

  9. Prairie chicken populations of the Sheyenne Delta in North Dakota, 1961-1987

    Science.gov (United States)

    Jerry D. Kobriger; David P. Vollink; Michael E. Mcneill; Kenneth F. Higgins

    1988-01-01

    Prairie chickens (Tympanuchus cupido pinnatus) were first censused on the Sheyenne Grasslands in 1961. The population was extremely low in the 1960's, gradually increased in the 1970's, and reached a peak of 410 in 1980. Sufficient evidence exists to link the increase in numbers of prairie chickens on the grasslands from 1961 through 1987...

  10. Effect of mid-summer haying on growth and reproduction in prairie forbs

    Science.gov (United States)

    Becky Begay; Helen M. Alexander; Erin Questad

    2011-01-01

    Mid-summer haying is a common management practice for prairies; plant species could differ in the effect of haying on subsequent growth and reproduction. We examined the effect of haying on prairie species by performing a clipping experiment. For each of seven species, sixteen plants were chosen and half were randomly assigned to a clipping treatment and half to a...

  11. Physiologic Reference Ranges for Captive Black-Tailed Prairie Dogs (Cynomys ludovicianus)

    Science.gov (United States)

    Keckler, M Shannon; Gallardo-Romero, Nadia F; Langham, Gregory L; Damon, Inger K; Karem, Kevin L; Carroll, Darin S

    2010-01-01

    The black-tailed prairie dog (Cynomys ludovicianus) is a member of the order Rodentia and the family Sciuridae. Ecologically, prairie dogs are a keystone species in prairie ecology. This species is used as an animal model for human gallbladder disease and diseases caused by infection with Clostridium difficile, Yersinia pestis, Francisella tularensis, and most recently, Orthopoxvirus. Despite increasing numbers of prairie dogs used in research and kept as pets, few data are available on their baseline physiology in animal facility housing conditions. To establish baseline physiologic reference ranges, we designed a study using 18 wild-caught black-tailed prairie dogs. Telemetry data were analyzed to establish circadian rhythms for activity and temperature. In addition, hematologic and serum chemistry analyses were performed. Baseline measurements were used to establish the mean for each animal, which then were compiled and analyzed to determine the reference ranges. Here we present physiologic data on serum chemistry and hematology profiles, as well as weight, core body temperature, and daily activity patterns for black-tailed prairie dogs. These results reflect the use of multiple measurements from species- and age-matched prairie dogs and likely will be useful to ecologists, scientists interested in using this animal model in research, and veterinarians caring for pet prairie dogs. PMID:20587156

  12. A novel approach for assessing density and range-wide abundance of prairie dogs

    Science.gov (United States)

    Aaron N. Facka; Paulette L. Ford; Gary W. Roemer

    2008-01-01

    Habitat loss, introduced disease, and government-sponsored eradication programs have caused population declines in all 5 species of prairie dogs. Black-tailed prairie dogs (Cynomys ludovicianus) currently occupy only about 2% of an extensive geographic range (160 million hectares) and were recently considered for listing under the United States...

  13. Elevated CO2 and warming induce substantial and persistent declines in forage quality irrespective of warming in mixed grass prairie

    Science.gov (United States)

    Increasing atmospheric [CO2] and temperature are expected to affect the productivity, species composition, biogeochemistry, and therefore the quantity and quality of forage available to herbivores in rangeland ecosystems. Both elevated CO2 (eCO2) and warming affect plant tissue chemistry through mul...

  14. Spatial heterogeneity and scale-dependent habitat selection for two sympatric raptors in mixed-grass prairie.

    Science.gov (United States)

    Atuo, Fidelis Akunke; O'Connell, Timothy John

    2017-08-01

    Sympatric predators are predicted to partition resources, especially under conditions of food limitation. Spatial heterogeneity that influences prey availability might play an important role in the scales at which potential competitors select habitat. We assessed potential mechanisms for coexistence by examining the role of heterogeneity in resource partitioning between sympatric raptors overwintering in the southern Great Plains. We conducted surveys for wintering Red-tailed hawk ( Buteo jamaicensis ) and Northern Harrier ( Circus cyanea ) at two state wildlife management areas in Oklahoma, USA. We used information from repeated distance sampling to project use locations in a GIS. We applied resource selection functions to model habitat selection at three scales and analyzed for niche partitioning using the outlying mean index. Habitat selection of the two predators was mediated by spatial heterogeneity. The two predators demonstrated significant fine-scale discrimination in habitat selection in homogeneous landscapes, but were more sympatric in heterogeneous landscapes. Red-tailed hawk used a variety of cover types in heterogeneous landscapes but specialized on riparian forest in homogeneous landscapes. Northern Harrier specialized on upland grasslands in homogeneous landscapes but selected more cover types in heterogeneous landscapes. Our study supports the growing body of evidence that landscapes can affect animal behaviors. In the system we studied, larger patches of primary land cover types were associated with greater allopatry in habitat selection between two potentially competing predators. Heterogeneity within the scale of raptor home ranges was associated with greater sympatry in use and less specialization in land cover types selected.

  15. Restoring fire as an ecological process in shortgrass prairie ecosystems: initial effects of prescribed burning during the dormant and growing seasons.

    Science.gov (United States)

    Brockway, Dale G; Gatewood, Richard G; Paris, Randi B

    2002-06-01

    Prior to Anglo-European settlement, fire was a major ecological process influencing the structure, composition and productivity of shortgrass prairie ecosystems on the Great Plains. However during the past 125 years, the frequency and extent of grassland fire has dramatically declined as a result of the systematic heavy grazing by large herds of domestic cattle and sheep which reduced the available levels of fine fuel and organized fire suppression efforts that succeeded in altering the natural fire regime. The greatly diminished role of recurrent fire in these ecosystems is thought to be responsible for ecologically adverse shifts in the composition, structure and diversity of these grasslands, leading specifically to the rise of ruderal species and invasion by less fire-tolerant species. The purpose of this study was to evaluate the ecological effects of fire season and frequency on the shortgrass prairie and to determine the means by which prescribed fire can best be restored in this ecosystem to provide the greatest benefit for numerous resource values. Plant cover, diversity, biomass and nutrient status, litter cover and soil chemistry were measured prior to and following fire treatments on a buffalograss-blue grama shortgrass prairie in northeastern New Mexico. Dormant-season fire was followed by increases in grass cover, forb cover, species richness and concentrations of foliar P, K, Ca, Mg and Mn. Growing-season fire produced declines in the cover of buffalograss, graminoids and forbs and increases in litter cover and levels of foliar P, K, Ca and Mn. Although no changes in soil chemistry were observed, both fire treatments caused decreases in herbaceous production, with standing biomass resulting from growing-season fire approximately 600 kg/ha and dormant-season fire approximately 1200 kg/ha, compared with controls approximately 1800 kg/ha. The initial findings of this long-term experiment suggest that dormant-season burning may be the preferable method

  16. Exploiting differential vegetation phenology for satellite-based mapping of semiarid grass vegetation in the southwestern United States and northern Mexico

    Science.gov (United States)

    Dye, Dennis G.; Middleton, Barry R.; Vogel, John M.; Wu, Zhuoting; Velasco, Miguel G.

    2016-01-01

    We developed and evaluated a methodology for subpixel discrimination and large-area mapping of the perennial warm-season (C4) grass component of vegetation cover in mixed-composition landscapes of the southwestern United States and northern Mexico. We describe the methodology within a general, conceptual framework that we identify as the differential vegetation phenology (DVP) paradigm. We introduce a DVP index, the Normalized Difference Phenometric Index (NDPI) that provides vegetation type-specific information at the subpixel scale by exploiting differential patterns of vegetation phenology detectable in time-series spectral vegetation index (VI) data from multispectral land imagers. We used modified soil-adjusted vegetation index (MSAVI2) data from Landsat to develop the NDPI, and MSAVI2 data from MODIS to compare its performance relative to one alternate DVP metric (difference of spring average MSAVI2 and summer maximum MSAVI2), and two simple, conventional VI metrics (summer average MSAVI2, summer maximum MSAVI2). The NDPI in a scaled form (NDPIs) performed best in predicting variation in perennial C4 grass cover as estimated from landscape photographs at 92 sites (R2 = 0.76, p landscapes of the Southwest, and potentially for monitoring of its response to drought, climate change, grazing and other factors, including land management. With appropriate adjustments, the method could potentially be used for subpixel discrimination and mapping of grass or other vegetation types in other regions where the vegetation components of the landscape exhibit contrasting seasonal patterns of phenology.

  17. Grass leaves as potential hominin dietary resources.

    Science.gov (United States)

    Paine, Oliver C C; Koppa, Abigale; Henry, Amanda G; Leichliter, Jennifer N; Codron, Daryl; Codron, Jacqueline; Lambert, Joanna E; Sponheimer, Matt

    2018-04-01

    Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C 4 component in the diets of most taxa, and grass leaves are the single most abundant C 4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i.e., high toughness) for hominins with bunodont dentition. Here, we compare the nutritional and mechanical properties of grass leaves with the plants growing alongside them in African savanna habitats. We also compare grass leaves to the leaves consumed by other hominoids and demonstrate that many, though by no means all, compare favorably with the nutritional and mechanical properties of known primate foods. Our data reveal that grass leaves exhibit tremendous variation and suggest that future reconstructions of hominin dietary ecology take a more nuanced approach when considering grass leaves as a potential hominin dietary resource. Copyright © 2017. Published by Elsevier Ltd.

  18. Linking Microbial Community Structure and Function During the Acidified Anaerobic Digestion of Grass

    Directory of Open Access Journals (Sweden)

    Aoife Joyce

    2018-03-01

    Full Text Available Harvesting valuable bioproducts from various renewable feedstocks is necessary for the critical development of a sustainable bioeconomy. Anaerobic digestion is a well-established technology for the conversion of wastewater and solid feedstocks to energy with the additional potential for production of process intermediates of high market values (e.g., carboxylates. In recent years, first-generation biofuels typically derived from food crops have been widely utilized as a renewable source of energy. The environmental and socioeconomic limitations of such strategy, however, have led to the development of second-generation biofuels utilizing, amongst other feedstocks, lignocellulosic biomass. In this context, the anaerobic digestion of perennial grass holds great promise for the conversion of sustainable renewable feedstock to energy and other process intermediates. The advancement of this technology however, and its implementation for industrial applications, relies on a greater understanding of the microbiome underpinning the process. To this end, microbial communities recovered from replicated anaerobic bioreactors digesting grass were analyzed. The bioreactors leachates were not buffered and acidic pH (between 5.5 and 6.3 prevailed at the time of sampling as a result of microbial activities. Community composition and transcriptionally active taxa were examined using 16S rRNA sequencing and microbial functions were investigated using metaproteomics. Bioreactor fraction, i.e., grass or leachate, was found to be the main discriminator of community analysis across the three molecular level of investigation (DNA, RNA, and proteins. Six taxa, namely Bacteroidia, Betaproteobacteria, Clostridia, Gammaproteobacteria, Methanomicrobia, and Negativicutes accounted for the large majority of the three datasets. The initial stages of grass hydrolysis were carried out by Bacteroidia, Gammaproteobacteria, and Negativicutes in the grass biofilms, in addition to

  19. Linking Microbial Community Structure and Function During the Acidified Anaerobic Digestion of Grass.

    Science.gov (United States)

    Joyce, Aoife; Ijaz, Umer Z; Nzeteu, Corine; Vaughan, Aoife; Shirran, Sally L; Botting, Catherine H; Quince, Christopher; O'Flaherty, Vincent; Abram, Florence

    2018-01-01

    Harvesting valuable bioproducts from various renewable feedstocks is necessary for the critical development of a sustainable bioeconomy. Anaerobic digestion is a well-established technology for the conversion of wastewater and solid feedstocks to energy with the additional potential for production of process intermediates of high market values (e.g., carboxylates). In recent years, first-generation biofuels typically derived from food crops have been widely utilized as a renewable source of energy. The environmental and socioeconomic limitations of such strategy, however, have led to the development of second-generation biofuels utilizing, amongst other feedstocks, lignocellulosic biomass. In this context, the anaerobic digestion of perennial grass holds great promise for the conversion of sustainable renewable feedstock to energy and other process intermediates. The advancement of this technology however, and its implementation for industrial applications, relies on a greater understanding of the microbiome underpinning the process. To this end, microbial communities recovered from replicated anaerobic bioreactors digesting grass were analyzed. The bioreactors leachates were not buffered and acidic pH (between 5.5 and 6.3) prevailed at the time of sampling as a result of microbial activities. Community composition and transcriptionally active taxa were examined using 16S rRNA sequencing and microbial functions were investigated using metaproteomics. Bioreactor fraction, i.e., grass or leachate, was found to be the main discriminator of community analysis across the three molecular level of investigation (DNA, RNA, and proteins). Six taxa, namely Bacteroidia, Betaproteobacteria, Clostridia, Gammaproteobacteria, Methanomicrobia, and Negativicutes accounted for the large majority of the three datasets. The initial stages of grass hydrolysis were carried out by Bacteroidia, Gammaproteobacteria, and Negativicutes in the grass biofilms, in addition to Clostridia in the

  20. A Hypothesis: Could Portable Natural Grass be a Risk Factor for Knee Injuries?

    Science.gov (United States)

    Orchard, John; Rodas, Gil; Til, Lluis; ArdevÒl, Jordi; Chivers, Ian

    2008-01-01

    Previous study has shown a likely link between increased shoe- surface traction and risk of knee Anterior Cruciate Ligament (ACL) injury. Portable natural grass systems are being used more often in sport, but no study to date has investigated their relative safety. By their nature, they must have high resistance to falling apart and therefore newly laid systems may be at risk of creating excessive shoe-surface traction. This study describes two clusters of knee injuries (particularly non-contact ACL injuries), each occurring to players of one professional football team at single venue, using portable grass, in a short space of time. The first series included two ACL injuries, one posterolateral complex disruption and one lateral ligament tear occurring in two rugby league games on a portable bermudagrass surface in Brisbane, Australia. The second series included four non-contact ACL injuries over a period of ten weeks in professional soccer games on a portable Kentucky bluegrass/perennial ryegrass surface in Barcelona, Spain. Possible intrinsic risk factors are discussed but there was no common risk shared by the players. Although no measures of traction were made at the Brisbane venue, average rotational traction was measured towards the end of the injury cluster at Camp Nou, Barcelona, to be 48 Nm. Chance undoubtedly had a part to play in these clusters, but the only obvious common risk factor was play on a portable natural grass surface soon after it was laid. Further study is required to determine whether portable natural grass systems may exhibit high shoe-surface traction soon after being laid and whether this could be a risk factor for knee injury. Key pointsExcessive shoe-surface traction is a hypothesised risk factor for knee ligament injuries, including anterior cruciate ligament injuries.Portable natural grass systems (by their nature in order to prevent grass rolls or squares from falling apart) will tend to exhibit high resistance to tearing when first

  1. Precipitation, Climate Change, and Parasitism of Prairie Dogs by Fleas that Transmit Plague.

    Science.gov (United States)

    Eads, David A; Hoogland, John L

    2017-08-01

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that can reduce the fitness of vertebrate hosts. Laboratory populations of fleas decline under dry conditions, implying that populations of fleas will also decline when precipitation is scarce under natural conditions. If precipitation and hence vegetative production are reduced, however, then herbivorous hosts might suffer declines in body condition and have weakened defenses against fleas, so that fleas will increase in abundance. We tested these competing hypotheses using information from 23 yr of research on 3 species of colonial prairie dogs in the western United States: Gunnison's prairie dog (Cynomys gunnisoni, 1989-1994), Utah prairie dog (Cynomys parvidens, 1996-2005), and white-tailed prairie dog (Cynomys leucurus, 2006-2012). For all 3 species, flea-counts per individual varied inversely with the number of days in the prior growing season with >10 mm of precipitation, an index of the number of precipitation events that might have caused a substantial, prolonged increase in soil moisture and vegetative production. Flea-counts per Utah prairie dog also varied inversely with cumulative precipitation of the prior growing season. Furthermore, flea-counts per Gunnison's and white-tailed prairie dog varied inversely with cumulative precipitation of the just-completed January and February. These results complement research on black-tailed prairie dog (Cynomys ludovicianus) and might have important ramifications for plague, a bacterial disease transmitted by fleas that devastates populations of prairie dogs. In particular, our results might help to explain why, at some colonies, epizootics of plague, which can kill >95% of prairie dogs, are more likely to occur during or shortly after periods of reduced precipitation. Climate change is projected to increase the frequency of droughts in the grasslands of western North America. If so, then climate change might affect the occurrence of plague epizootics

  2. Grass Biomethane for Agriculture and Energy

    DEFF Research Database (Denmark)

    Korres, N.E.; Thamsiriroj, T.; Smith, B.

    2011-01-01

    have advanced the role of grassland as a renewable source of energy in grass biomethane production with various environmental and socio-economic benefits. It is underlined that the essential question whether the gaseous biofuel meets the EU sustainability criteria of 60% greenhouse gas emission savings...... by 2020 can be met since savings up to 89.4% under various scenarios can be achieved. Grass biomethane production compared to other liquid biofuels either when these are produced by indigenous of imported feedstocks is very promising. Grass biomethane, given the mature and well known technology...

  3. Perennial ryegrass for dairy cows: effects of cultivar on herbage intake during grazing

    NARCIS (Netherlands)

    Smit, H.J.

    2005-01-01

    Keywords:Perennial ryegrass, Lolium perenne , sward morphology, sward cutting, n-alkanes, herbage intake, selection, preference.Perennial ryegrass ( Lolium perenne L.) is the most important species for feeding dairy cows. The majority of the farmers in the Netherlands graze their

  4. Perennial wheat lines have highly admixed population structure and elevated rates of outcrossing.

    Science.gov (United States)

    Perennial wheat has been proposed to alleviate long standing issues with soil erosion in annual cropping systems, while supporting rural communities and providing grain farmers with a marketable climate-resilient crop. The Washington State University perennial wheat breeding program has created sev...

  5. Adaptive management of perennial pepperweed for endangered specias and tidal marsh recovery

    Science.gov (United States)

    Perennial pepperweed has invaded a wide range of habitat types in the far west. In the San Francisco Estuary, dense infestations have impacted sensitive tidal wetlands and compromised endangered species recovery efforts. An adaptive management effort to reduce perennial pepperweed was initiated by...

  6. Control of perennial weeds by mechanical methods and anaerobic soil disinfection

    NARCIS (Netherlands)

    Huiting, H.F.; Bleeker, P.O.; Riemens, M.M.

    2011-01-01

    Perennial weeds are difficult to control and ask for a specific approach. During the most recent years it has even become a great challenge to control these weeds in conventional farming systems, although in comparison effective perennial weed control in organic farming systems remains more

  7. Pastures to Prairies to Pools: An Update on Natural Resource Damages Settlement Projects at the Fernald Preserve - 13198

    Energy Technology Data Exchange (ETDEWEB)

    Powell, Jane [Fernald Preserve Site Manager, DOE Office of Legacy Management, Harrison, Ohio (United States); Schneider, Tom [Fernald Project Manager, Ohio Environmental Protection Agency, Dayton, Ohio (United States); Hertel, Bill [Project Manager, S.M. Stoller Corporation, Harrison, Ohio (United States); Homer, John [Environmental Scientist, S.M. Stoller Corporation, Harrison, Ohio (United States)

    2013-07-01

    The DOE Office of Legacy Management oversees implementation and monitoring of two ecological restoration projects at the Fernald Preserve, Fernald, Ohio, that are funded through a CERCLA natural resource damage settlement. Planning and implementation of on-property ecological restoration projects is one component of compensation for natural resource injury. The Paddys Run Tributary Project involves creation of vernal pool wetland habitat with adjacent forest restoration. The Triangle Area Project is a mesic tall-grass prairie establishment, similar to other efforts at the Fernald Preserve. The goal of the Fernald Natural Resource Trustees is to establish habitat for Ambystomatid salamander species, as well as grassland birds. Field implementation of these projects was completed in May 2012. Herbaceous cover and woody vegetation survival was determined in August and September 2012. Results show successful establishment of native vegetation. Additional monitoring will be needed to determine whether project goals have been met. As with the rest of the Fernald Preserve, ecological restoration has helped turn a DOE liability into a community asset. (authors)

  8. Pastures to Prairies to Pools: An Update on Natural Resource Damages Settlement Projects at the Fernald Preserve - 13198

    International Nuclear Information System (INIS)

    Powell, Jane; Schneider, Tom; Hertel, Bill; Homer, John

    2013-01-01

    The DOE Office of Legacy Management oversees implementation and monitoring of two ecological restoration projects at the Fernald Preserve, Fernald, Ohio, that are funded through a CERCLA natural resource damage settlement. Planning and implementation of on-property ecological restoration projects is one component of compensation for natural resource injury. The Paddys Run Tributary Project involves creation of vernal pool wetland habitat with adjacent forest restoration. The Triangle Area Project is a mesic tall-grass prairie establishment, similar to other efforts at the Fernald Preserve. The goal of the Fernald Natural Resource Trustees is to establish habitat for Ambystomatid salamander species, as well as grassland birds. Field implementation of these projects was completed in May 2012. Herbaceous cover and woody vegetation survival was determined in August and September 2012. Results show successful establishment of native vegetation. Additional monitoring will be needed to determine whether project goals have been met. As with the rest of the Fernald Preserve, ecological restoration has helped turn a DOE liability into a community asset. (authors)

  9. Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

    Energy Technology Data Exchange (ETDEWEB)

    Schulman, Al

    2009-08-09

    Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops

  10. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  11. Fusarium-induced diseases of tropical, perennial crops.

    Science.gov (United States)

    Ploetz, Randy C

    2006-06-01

    ABSTRACT The world's oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. This and subsequent papers describe diseases of tropical, perennial plants that are caused by Fusarium spp. Many of these are economically significant, difficult to manage, and of scientific interest. Some represent coevolved patho-systems (e.g., Panama disease, tracheomycosis of coffee, fusariosis of pineapple, and Fusarium wilt of oil palm), whereas others may be new-encounter diseases or are caused by generalist pathogens (cushion gall of cacao). New vector relationships are evident in other pathosystems (e.g., mango malformation), and two or more pathogens have been shown to cause some of the diseases (Panama disease and tracheomycosis of coffee). More work on these pathosystems is warranted as they could reveal much about the evolution of plant pathogens and the important diseases they cause.

  12. Grass survey of the Itremo Massif records endemic central highland ...

    African Journals Online (AJOL)

    Twenty species are endemic to the central highlands, and a further 1 4 species are restricted to Madagascar. Five ecological groups of grasses were identified in the Itremo Massif: shade species in gallery forests, open wet area species, fire grasses, anthropogenic disturbance associated grasses and rock-dwelling grasses.

  13. Modelling interactions in grass-clover mixtures

    NARCIS (Netherlands)

    Nassiri Mahallati, M.

    1998-01-01

    The study described in this thesis focuses on a quantitative understanding of the complex interactions in binary mixtures of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) under cutting. The first part of the study describes the dynamics of growth, production

  14. Efficacy of montelukast for treating perennial allergic rhinitis.

    Science.gov (United States)

    Philip, George; Williams-Herman, Debora; Patel, Piyush; Weinstein, Steven F; Alon, Achilles; Gilles, Leen; Tozzi, Carol A; Dass, S Balachandra; Reiss, Theodore F

    2007-01-01

    Perennial allergic rhinitis (PAR) is a chronic inflammatory nasal condition in individuals exposed year-round to allergens. This was a double-blind study of 15- to 85-year-old patients randomly allocated to montelukast, 10 mg (n=630), placebo (n=613), or the positive control cetirizine, 10 mg (n=122) for 6 weeks. The primary efficacy end point was change from baseline in Daytime Nasal Symptoms Score (DNSS; mean of congestion, rhinorrhea, sneezing, and itching scores, rated daily by patients [scale: 0=none to 3=severe]) averaged during the initial 4 weeks (primary analysis) or entire 6 weeks of treatment. Also assessed were combined post hoc results of primary end point data from this study and another similarly designed study (Patel P, et al. Randomized, double-blind, placebo-controlled study of montelukast for treating perennial allergic rhinitis, Ann Allergy Asthma Immunol 95:551, 2005). Over 4 weeks, montelukast showed numerical improvement over placebo in DNSS (least-squares mean difference of -0.04 [95% confidence interval (CI}, -0.09, 0.01]); the difference between cetirizine and placebo was significant: -0.10 (95% CI, -0.19, -0.01). However, when averaged over 6 weeks, neither active treatment was significantly different from placebo. The Rhinoconjunctivitis Quality-of-Life score was significantly improved by montelukast (p < 0.05), but not by cetirizine, during 4 and 6 weeks. The treatment effect of montelukast, but not cetirizine, generally remained consistent through the 6 weeks of treatment. In pooled data, montelukast consistently improved DNSS versus placebo during all 6 weeks of treatment (-0.07 [95% CI, -0.10, -0.041). In conclusion, montelukast produced numerical improvement in daytime nasal symptoms and significant improvement in quality of life. In a pooled post hoc analysis, montelukast provided consistent improvement in daytime nasal symptoms over 6 weeks, supportive of an overall benefit in PAR.

  15. Pampas Grass - Orange Co. [ds351

    Data.gov (United States)

    California Natural Resource Agency — This dataset provides the known distribution of pampas grass (Cortaderia selloana) in southern Orange County. The surveys were conducted from May to June, 2007 and...

  16. Tree-grass interactions in savannas

    CSIR Research Space (South Africa)

    Scholes, RJ

    1997-01-01

    Full Text Available Savannas occur where trees and grasses interact to create a biome that is neither grassland nor forest. Woody and gramineous plants interact by many mechanisms, some negative (competition) and some positive (facilitation). The strength and sign...

  17. POTENTIALS OF AGRICULTURAL WASTE AND GRASSES IN ...

    African Journals Online (AJOL)

    Shima

    Potentials of some agricultural waste and grasses were investigated. ... to education, printing, publishing and ... technical form, paper is an aqueous deposit ..... Period of. Soaking. Overnight. Overnight. Overnight. Overnight. Overnight.

  18. Grasses for energy production: hydrological guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.L.

    2003-07-01

    This report provides hydrological guidelines for growers, land and water resource managers, environmental groups and other parties interested in utilising grasses for energy production. The aim of the report is to help interested parties decide if a location is suitable for planting energy grasses by considering whether potential hydrological impacts will have an adverse effect on crop productivity and yield. The guidelines consider: the water use of energy grasses compared with other crops; the factors governing water use; the water requirements for a productive crop; and the likely impacts on the availability and quantity of water. The report points out that there are still gaps in our knowledge of the processes controlling the water use and growth of energy grasses and notes that, in some situations, there will be considerable uncertainty in predictions of water use and the magnitude of the associated hydrological impacts.

  19. Imaging spectroscopy for characterisation of grass swards

    NARCIS (Netherlands)

    Schut, A.G.T.

    2003-01-01

    Keywords: Imaging spectroscopy, imaging spectrometry, remote sensing, reflection, reflectance, grass sward, white clover, recognition, characterisation, ground cover, growth monitoring, stress detection, heterogeneity quantification

    The potential of imaging spectroscopy as a tool for

  20. Karl Konrad Grass jumalainimeste uurijana / Alar Laats

    Index Scriptorium Estoniae

    Laats, Alar

    2006-01-01

    Karl Konrad Grass oli 19. sajandil Dorpati keiserliku ülikooli usuteaduskonna Uue Testamendi õppejõud, kes tegeles hobi korras idakristluse (vene sektid) uurimisega. Tema peateoseks on uurimus "Die russischen Sekten". Ettekanne konverentsil 15.-16. aprill 2005. a.

  1. Sensibilidade do capim-capivara a herbicidas Sensitivity of West Indian Marsh Grass to herbicides

    Directory of Open Access Journals (Sweden)

    K.S. Silva

    2012-12-01

    Full Text Available Dois experimentos foram conduzidos em casa de vegetação com o objetivo de identificar, através de curvas de dose-resposta, a sensibilidade de plantas jovens e perenizadas de capim-capivara a doses crescentes (0, 25, 50, 75, 100, 125, 150, 175 e 200% da dose recomendada para gramíneas perenes de cyhalofop-butyl (315 g i.a. ha-1, imazapic + imazapyr (24,5 g e.a. ha-1 + 73,5 g e.a. ha-1, glyphosate (2.160 g e.a. ha-1 e amônio glufosinate (900 g i.a. ha-1. O experimento 1 foi conduzido de janeiro a março de 2010, e o experimento 2, de janeiro de 2010 a janeiro de 2011. Plantas jovens apresentaram maior sensibilidade aos herbicidas amônio glufosinate e cyhalofop-butyl, entretanto, a morte das plantas ocorreu somente quando tratadas com glyphosate e a mistura formulada de imazapic + imazapyr. Em plantas perenizadas, os herbicidas não proporcionaram controle satisfatório.Two experiments were conducted under greenhouse conditions to identify, based on dose-response curves, the sensitivity of young and perennial plants of West Indian Marsh grass to increasing doses (0, 25, 50, 75, 100, 125, 150, 175 and 200% of the recommended dose for perennial grasses of cyhalofop butyl (315gc.p. ha-1, imazapic + imazapyr (24.5gc.p. ha-1 + 73.5gc.p. ha-1, glyphosate (2,160gc.p. ha-1 and ammonium glufosinate (900gc.p. ha-1. Experiment I was conducted from January to March 2010 and Experiment II, from January 2010 to January 2011. Young plants showed higher sensitivity to ammonium glufosinate and cyhalofop butyl; however, death occurred only when the plants were treated with glyphosate and a formulated mixture of Imazapic + Imazapyr. The herbicides did not provide satisfactory control against the perennial plants.

  2. Season and application rates affect vaccine bait consumption by prairie dogs in Colorado and Utah, USA

    Science.gov (United States)

    Tripp, Daniel W.; Rocke, Tonie E.; Streich, Sean P.; Brown, Nathanael L.; Fernandez, Julia Rodriguez-Ramos; Miller, Michael W.

    2014-01-01

    Plague, a zoonotic disease caused by the bacterium Yersinia pestis, causes high rates of mortality in prairie dogs (Cynomys spp.). An oral vaccine against plague has been developed for prairie dogs along with a palatable bait to deliver vaccine and a biomarker to track bait consumption. We conducted field trials between September 2009 and September 2012 to develop recommendations for bait distribution to deliver plague vaccine to prairie dogs. The objectives were to evaluate the use of the biomarker, rhodamine B, in field settings to compare bait distribution strategies, to compare uptake of baits distributed at different densities, to assess seasonal effects on bait uptake, and to measure bait uptake by nontarget small mammal species. Rhodamine B effectively marked prairie dogs' whiskers during these field trials. To compare bait distribution strategies, we applied baits around active burrows or along transects at densities of 32, 65, and 130 baits/ha. Distributing baits at active burrows or by transect did not affect uptake by prairie dogs. Distributing baits at rates of ≥65/ha (or ≥1 bait/active burrow) produced optimal uptake, and bait uptake by prairie dogs in the autumn was superior to uptake in the spring. Six other species of small mammals consumed baits during these trials. All four species of tested prairie dogs readily consumed the baits, demonstrating that vaccine uptake will not be an obstacle to plague control via oral vaccination.

  3. Factors influencing uptake of sylvatic plague vaccine baits by prairie dogs

    Science.gov (United States)

    Abbott, Rachel C.; Russell, Robin E.; Richgels, Katherine; Tripp, Daniel W.; Matchett, Marc R.; Biggins, Dean E.; Rocke, Tonie E.

    2017-01-01

    Sylvatic plague vaccine (SPV) is a virally vectored bait-delivered vaccine expressing Yersinia pestis antigens that can protect prairie dogs (Cynomys spp.) from plague and has potential utility as a management tool. In a large-scale 3-year field trial, SPV-laden baits containing the biomarker rhodamine B (used to determine bait consumption) were distributed annually at a rate of approximately 100–125 baits/hectare along transects at 58 plots encompassing the geographic ranges of four species of prairie dogs. We assessed site- and individual-level factors related to bait uptake in prairie dogs to determine which were associated with bait uptake rates. Overall bait uptake for 7820 prairie dogs sampled was 70% (95% C.I. 69.9–72.0). Factors influencing bait uptake rates by prairie dogs varied by species, however, in general, heavier animals had greater bait uptake rates. Vegetation quality and day of baiting influenced this relationship for black-tailed, Gunnison’s, and Utah prairie dogs. For these species, baiting later in the season, when normalized difference vegetation indices (a measure of green vegetation density) are lower, improves bait uptake by smaller animals. Consideration of these factors can aid in the development of species-specific SPV baiting strategies that maximize bait uptake and subsequent immunization of prairie dogs against plague.

  4. Genetic compatibility determines endophyte-grass combinations.

    Directory of Open Access Journals (Sweden)

    Kari Saikkonen

    Full Text Available Even highly mutually beneficial microbial-plant interactions, such as mycorrhizal- and rhizobial-plant exchanges, involve selfishness, cheating and power-struggles between the partners, which depending on prevailing selective pressures, lead to a continuum of interactions from antagonistic to mutualistic. Using manipulated grass-endophyte combinations in a five year common garden experiment, we show that grass genotypes and genetic mismatches constrain genetic combinations between the vertically (via host seeds transmitted endophytes and the out-crossing host, thereby reducing infections in established grass populations. Infections were lost in both grass tillers and seedlings in F(1 and F(2 generations, respectively. Experimental plants were collected as seeds from two different environments, i.e., meadows and nearby riverbanks. Endophyte-related benefits to the host included an increased number of inflorescences, but only in meadow plants and not until the last growing season of the experiment. Our results illustrate the importance of genetic host specificity and trans-generational maternal effects on the genetic structure of a host population, which act as destabilizing forces in endophyte-grass symbioses. We propose that (1 genetic mismatches may act as a buffering mechanism against highly competitive endophyte-grass genotype combinations threatening the biodiversity of grassland communities and (2 these mismatches should be acknowledged, particularly in breeding programmes aimed at harnessing systemic and heritable endophytes to improve the agriculturally valuable characteristics of cultivars.

  5. Climate change and prairie pothole wetlands: mitigating water-level and hydroperiod effects through upland management

    Science.gov (United States)

    Renton, David A.; Mushet, David M.; DeKeyser, Edward S.

    2015-01-01

    Prairie pothole wetlands offer crucial habitat for North America’s waterfowl populations. The wetlands also support an abundance of other species and provide ecological services valued by society. The hydrology of prairie pothole wetlands is dependent on atmospheric interactions. Therefore, changes to the region’s climate can have profound effects on wetland hydrology. The relevant literature related to climate change and upland management effects on prairie pothole wetland water levels and hydroperiods was reviewed. Climate change is widely expected to affect water levels and hydroperiods of prairie pothole wetlands, as well as the biota and ecological services that the wetlands support. In general, hydrologic model projections that incorporate future climate change scenarios forecast lower water levels in prairie pothole wetlands and longer periods spent in a dry condition, despite potential increases in precipitation. However, the extreme natural variability in climate and hydrology of prairie pothole wetlands necessitates caution when interpreting model results. Recent changes in weather patterns throughout much of the Prairie Pothole Region have been in increased precipitation that results in increased water inputs to wetlands above losses associated with warmer temperatures. However, observed precipitation increases are within the range of natural climate variability and therefore, may not persist. Identifying management techniques with the potential to affect water inputs to prairie pothole wetlands would provide increased options for managers when dealing with the uncertainties associated with a changing climate. Several grassland management techniques (for example, grazing and burning) have the potential to affect water levels and hydroperiods of prairie pothole by affecting infiltration, evapotranspiration, and snow deposition.

  6. Spatial variation in keystone effects: Small mammal diversity associated with black-tailed prairie dog colonies

    Science.gov (United States)

    Cully, J.F.; Collinge, S.K.; Van Nimwegen, R. E.; Ray, C.; Johnson, W.C.; Thiagarajan, Bala; Conlin, D.B.; Holmes, B.E.

    2010-01-01

    Species with extensive geographic ranges may interact with different species assemblages at distant locations, with the result that the nature of the interactions may vary spatially. Black-tailed prairie dogs Cynomys ludovicianus occur from Canada to Mexico in grasslands of the western Great Plains of North America. Black-tailed prairie dogs alter vegetation and dig extensive burrow systems that alter grassland habitats for plants and other animal species. These alterations of habitat justify the descriptor " ecological engineer," and the resulting changes in species composition have earned them status as a keystone species. We examined the impact of black-tailed prairie dogs on small mammal assemblages by trapping at on- and off-colony locations at eight study areas across the species' geographic range. We posed 2 nested hypotheses: 1) prairie dogs function as a keystone species for other rodent species; and 2) the keystone role varies spatially. Assuming that it does, we asked what are the sources of the variation? Black-tailed prairie dogs consistently functioned as a keystone species in that there were strong statistically significant differences in community composition on versus off prairie dog colonies across the species range in prairie grassland. Small mammal species composition varied along both latitudinal and longitudinal gradients, and species richness varied from 4 to 11. Assemblages closer together were more similar; such correlations approximately doubled when including only on- or off-colony grids. Black-tailed prairie dogs had a significant effect on associated rodent assemblages that varied regionally, dependent upon the composition of the local rodent species pool. Over the range of the black-tailed prairie dog, on-colony rodent richness and evenness were less variable, and species composition was more consistent than off-colony assemblages. ?? 2010 The Authors.

  7. Lesser prairie-chicken avoidance of trees in a grassland landscape

    Science.gov (United States)

    Lautenbach, Joseph M.; Plumb, Reid T.; Robinson, Samantha G.; Hagen, Christian A.; Haukos, David A.; Pitman, James C.

    2016-01-01

    Grasslands are among the most imperiled ecosystems in North America. Reasons that grasslands are threatened include conversion to row-crop agriculture, fragmentation, and changes in fire regimes. The reduction of fire processes in remaining prairies has resulted in tree encroachment and establishment in grasslands, further reducing grassland quantity and quality. Grassland birds have been experiencing precipitous population declines in recent decades, commensurate with landscape changes to grasslands. The lesser prairie-chicken (Tympanuchus pallidicinctus Ridgway) is a declining species of prairie grouse of conservation concern. We used second- and third-order habitat selection metrics to test if female lesser prairie-chickens avoid grasslands where trees were present. Our results indicated that female lesser prairie-chickens selected habitats avoiding the nearest trees by 283 m on average, nearly twice as far as would be expected at random. Lesser prairie-chickens were 40 times more likely to use habitats with tree densities of 0 trees ∙ ha− 1 than habitats with 5 trees ∙ ha− 1. Probability of use indicated that lesser prairie-chickens were 19 times more likely to use habitats 1000 m from the nearest tree when compared with using habitats 0 m from the nearest tree. Nest survival was not affected at densities 2 trees ∙ ha− 1. Avoidance of trees could be due to perceived increased predation risk, reduced habitat quality, or a combination of these potentially confounding factors. Preventing further establishment and expansion of trees in landscapes occupied by lesser prairie-chickens could contribute to the continued persistence of the species. Additionally, restoring grasslands through tree removal may facilitate conservation efforts for grassland species such as the lesser prairie-chicken by improving habitat quality and promoting expansion of occupied range.

  8. Treatment with grass allergen peptides improves symptoms of grass pollen-induced allergic rhinoconjunctivitis.

    Science.gov (United States)

    Ellis, Anne K; Frankish, Charles W; O'Hehir, Robyn E; Armstrong, Kristen; Steacy, Lisa; Larché, Mark; Hafner, Roderick P

    2017-08-01

    Synthetic peptide immunoregulatory epitopes are a new class of immunotherapy to treat allergic rhinoconjunctivitis (ARC). Grass allergen peptides, comprising 7 synthetic T-cell epitopes derived from Cyn d 1, Lol p 5, Dac g 5, Hol l 5, and Phl p 5, is investigated for treatment of grass pollen-induced ARC. We sought to evaluate the efficacy, safety, and tolerability of intradermally administered grass allergen peptides. A multicenter, randomized, double-blind, placebo-controlled study evaluated 3 regimens of grass allergen peptides versus placebo in patients with grass pollen-induced allergy (18-65 years). After a 4-day baseline challenge to rye grass in the environmental exposure unit (EEU), subjects were randomized to receive grass allergen peptides at 6 nmol at 2-week intervals for a total of 8 doses (8x6Q2W), grass allergen peptides at 12 nmol at 4-week intervals for a total of 4 doses (4x12Q4W), or grass allergen peptides at 12 nmol at 2-week intervals for a total of 8 doses (8x12Q2W) or placebo and treated before the grass pollen season. The primary efficacy end point was change from baseline in total rhinoconjunctivitis symptom score across days 2 to 4 of a 4-day posttreatment challenge (PTC) in the EEU after the grass pollen season. Secondary efficacy end points and safety were also assessed. Two hundred eighty-two subjects were randomized. Significantly greater improvement (reduction of total rhinoconjunctivitis symptom score from baseline to PTC) occurred across days 2 to 4 with grass allergen peptide 8x6Q2W versus placebo (-5.4 vs -3.8, respectively; P = .0346). Greater improvement at PTC also occurred for grass allergen peptide 8x6Q2W versus placebo (P = .0403) in patients with more symptomatic ARC. No safety signals were detected. Grass allergen peptide 8x6Q2W significantly improved ARC symptoms after rye grass allergen challenge in an EEU with an acceptable safety profile. Copyright © 2017 American Academy of Allergy, Asthma & Immunology

  9. Estimating legume N-2 fixation in grass-clover mixtures of a grazed organic cropping system using two N-15 methods

    DEFF Research Database (Denmark)

    Vinther, F.P.; Jensen, E.S.

    2000-01-01

    The input of Nitrogen (N) through symbiotic N-2 fixation (SNF) in grass-clover mixtures was determined in an organic cropping. system for grazing during 3 years. The mixture of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) was established by undersowing in spring...... barley (Hordeum vulgare L.) and maintained subsequently for two production years. Dinitrogen fixation was determined using the N-15 isotope dilution techniques and two labelling procedures. Using either pre-labelling of the soil with immobilisation of the N-15 by addition of a carbon source before...

  10. Mine spoil prairies expand critical habitat for endangered and threatened amphibian and reptile species

    Science.gov (United States)

    Lannoo, Michael J.; Kinney, Vanessa C.; Heemeyer, Jennifer L.; Engbrecht, Nathan J.; Gallant, Alisa L.; Klaver, Robert W.

    2009-01-01

    Coal extraction has been occurring in the Midwestern United States for over a century. Despite the pre-mining history of the landscape as woodlands, spent surface coalfields are often reclaimed to grasslands. We assessed amphibian and reptile species on a large tract of coal spoil prairie and found 13 species of amphibians (nine frog and four salamander species) and 19 species of reptiles (one lizard, five turtle, and 13 snake species). Two state-endangered and three state species of special concern were documented. The amphibian diversity at our study site was comparable to the diversity found at a large restored prairie situated 175 km north, within the historic prairie peninsula.

  11. Accelerated development in Johnsongrass seedlings (Sorghum halepense) suppresses the growth of native grasses through size-asymmetric competition.

    Science.gov (United States)

    Schwinning, Susanne; Meckel, Heather; Reichmann, Lara G; Polley, H Wayne; Fay, Philip A

    2017-01-01

    Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparius) and switchgrass (Panicum virgatum). We predicted that a) the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b) competitive effect and response would be negatively correlated and c) soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding) ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass critical mechanism by which exotic invasive species displace functionally similar native species and alter the functional dynamics of native communities.

  12. Cumulative drought and land-use impacts on perennial vegetation across a North American dryland region

    Science.gov (United States)

    Munson, Seth M.; Long, A. Lexine; Wallace, Cynthia; Webb, Robert H.

    2016-01-01

    Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties and initiate land degradation processes. We tracked changes of perennial vegetation using remote sensing to address the question of how prolonged drought and land-use intensification have affected perennial vegetation cover across a desert region in the early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah and northwestern Arizona, USA. Methods We coupled the Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) with ground-based measurements of perennial vegetation cover taken in about 2000 and about 2010. Using the difference between these years, we determined perennial vegetation changes in the early 21st century and related these shifts to climate, soil and landscape properties, and patterns of land use. Results We found a good fit between MODIS-EVI and perennial vegetation cover (2000: R2 = 0.83 and 2010: R2 = 0.74). The southwestern, far southeastern and central Mojave Desert had large declines in perennial vegetation cover in the early 21st century, while the northeastern and southeastern portions of the desert had increases. These changes were explained by 10-yr precipitation anomalies, particularly in the cool season and during extreme dry or wet years. Areas heavily impacted by visitor use or wildfire lost perennial vegetation cover, and vegetation in protected areas increased to a greater degree than in unprotected areas. Conclusions We find that we can extrapolate previously documented declines of perennial plant cover to an entire desert, and demonstrate that prolonged water shortages coupled with land-use intensification create identifiable patterns of vegetation change in dryland regions.

  13. Nutritional value of cabbage and kikuyu grass as food for grass carp ...

    African Journals Online (AJOL)

    and digestibility coefficients were obtained for the protein, fibre, ash and fat contents of both ... Cabbage is a superior feed compared to grass for raising grass carp and a suitable low-cost alternative ... Materials and Methods ... from jumping out and was fitted with an air lift under- .... In: Aquatic weeds in South East Asia.

  14. Gene Expression Profiling of Grass Carp (Ctenopharyngodon idellus and Crisp Grass Carp

    Directory of Open Access Journals (Sweden)

    Ermeng Yu

    2014-01-01

    Full Text Available Grass carp (Ctenopharyngodon idellus is one of the most important freshwater fish that is native to China, and crisp grass carp is a kind of high value-added fishes which have higher muscle firmness. To investigate biological functions and possible signal transduction pathways that address muscle firmness increase of crisp grass carp, microarray analysis of 14,900 transcripts was performed. Compared with grass carp, 127 genes were upregulated and 114 genes were downregulated in crisp grass carp. Gene ontology (GO analysis revealed 30 GOs of differentially expressed genes in crisp grass carp. And strong correlation with muscle firmness increase of crisp grass carp was found for these genes from differentiation of muscle fibers and deposition of ECM, and also glycolysis/gluconeogenesis pathway and calcium metabolism may contribute to muscle firmness increase. In addition, a number of genes with unknown functions may be related to muscle firmness, and these genes are still further explored. Overall, these results had been demonstrated to play important roles in clarifying the molecular mechanism of muscle firmness increase in crisp grass carp.

  15. Different techniques to study rumen fermentation characteristics of maturing grass and grass silage

    NARCIS (Netherlands)

    Cone, J.W.; Gelder, van A.H.; Soliman, I.A.; Visser, de H.; Vuuren, van A.M.

    1999-01-01

    Grass samples were harvested during the 1993 growing season after a precut on April 27, 1993 and were stored frozen or left to ensile in 30-L buckets. Effects on chemical composition and fermentation kinetics of the maturation of the grass and of ensiling were investigated. Chemical composition and

  16. Analysis of the soil food web structure under grass and grass clover

    NARCIS (Netherlands)

    Eekeren, van N.J.M.; Smeding, F.W.; Vries, de F.T.; Bloem, J.

    2006-01-01

    The below ground biodiversity of soil organisms plays an important role in the functioning of the the soil ecosystem, and consequently the above ground plant production. The objective of this study is to investigate the effect of grass or grass-clover in combination with fertilisation on the soil

  17. Post-ruminal digestibility of crude protein from grass and grass silages in cows

    NARCIS (Netherlands)

    Cone, J.W.; Gelder, van A.H.; Mathijssen-Kamman, A.A.; Hindle, V.A.

    2006-01-01

    Grass samples were grown on a clay or sandy soil, fertilised with 150 or 300 kg N/ha per year, and harvested on different days during two consecutive growing seasons. The grass samples were stored frozen or ensiled after wilting to approximately 250 or 450 g DM/kg. The recoveries of crude protein

  18. Immunochemical studies of Lolium perenne (rye grass) pollen allergens, Lol p I, II, and III.

    Science.gov (United States)

    Ansari, A A; Kihara, T K; Marsh, D G

    1987-12-15

    It was reported earlier that human immune responses to three perennial rye grass (Lolium perenne) pollen allergens, Lol p I, II, and III, are associated with histocompatibility leukocyte antigen (HLA)-DR3. Rye-allergic people are often concordantly sensitive to all three of these allergens. Since earlier studies suggested that these antigens are non-cross-reactive, their immunologic relatedness by double antibody radioimmunoassay (DARIA) was studied in order to understand further the immunochemical basis for the concordant recognition of the three allergens. Direct binding DARIA studies were performed with human sera from 189 allergic subjects. Inhibition DARIA studies were carried out with 17 human sera from grass-allergic patients who were on grass immunotherapy, one goat anti-serum, and six rabbit antisera. None of the sera detected any significant degree of two-way cross-reactivity between Lol p I and II, or between Lol p I and III. However, the degree of two-way cross-reactivity between Lol p II and III exhibited by individual human and animal antisera varied between undetectable and 100%. In general, the degree of cross-reactivity between Lol p II and III was higher among human sera than among animal sera. Taken together with earlier findings that antibody responses to Lol p I, II and III are associated with HLA-HDR3, and that most Lol p II and III responders are also Lol p I responders, but not vice versa, our present results suggest the following: the HLA-DR3-encoded Ia molecule recognizes a similar immunodominant Ia recognition site (agretope) shared between Lol p I and Lol p II and/or III; in addition, Lol p I appears to contain unique Ia recognition site(s) not present in Lol p II and III. However, further epitope analyses are required to investigate these possibilities.

  19. Energy sorghum--a genetic model for the design of C4 grass bioenergy crops.

    Science.gov (United States)

    Mullet, John; Morishige, Daryl; McCormick, Ryan; Truong, Sandra; Hilley, Josie; McKinley, Brian; Anderson, Robert; Olson, Sara N; Rooney, William

    2014-07-01

    Sorghum is emerging as an excellent genetic model for the design of C4 grass bioenergy crops. Annual energy Sorghum hybrids also serve as a source of biomass for bioenergy production. Elucidation of Sorghum's flowering time gene regulatory network, and identification of complementary alleles for photoperiod sensitivity, enabled large-scale generation of energy Sorghum hybrids for testing and commercial use. Energy Sorghum hybrids with long vegetative growth phases were found to accumulate more than twice as much biomass as grain Sorghum, owing to extended growing seasons, greater light interception, and higher radiation use efficiency. High biomass yield, efficient nitrogen recycling, and preferential accumulation of stem biomass with low nitrogen content contributed to energy Sorghum's elevated nitrogen use efficiency. Sorghum's integrated genetics-genomics-breeding platform, diverse germplasm, and the opportunity for annual testing of new genetic designs in controlled environments and in multiple field locations is aiding fundamental discovery, and accelerating the improvement of biomass yield and optimization of composition for biofuels production. Recent advances in wide hybridization between Sorghum and other C4 grasses could allow the deployment of improved genetic designs of annual energy Sorghums in the form of wide-hybrid perennial crops. The current trajectory of energy Sorghum genetic improvement indicates that it will be possible to sustainably produce biofuels from C4 grass bioenergy crops that are cost competitive with petroleum-based transportation fuels. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. [A comparative study on seed germination of 15 grass species in Keeqin Sandyland].

    Science.gov (United States)

    Liu, Zhimin; Li, Xuehua; Li, Rongping; Jiang, Deming; Cao, Chengyou

    2003-09-01

    A laboratory study was made on the germination characteristics of freshly-collected seeds of grass species at the Wulanaodu area of Keeqin Sandyland in Eastern Inner-Mongolia. Of the 15 species examined, 8 species including Clinelymus dahuricus, Cleistogenes squarrosa, Pappophorum boreale, Spodiopogon sibiricus, Phragmites communis, Chloris virgata, Arundinella hirta, Pennisetum alopecuroides had a germination rate of over 80%, but 4 species including Echinochloa hispidula, Hemarthria compressa, Tragus berteronianus and Setaria viridis had a value of less than 10%. Spodiopogon sibiricus, Eragrostis pilosa, Phragmites communis, Chloris virgata, Clinelymus dahuricus, Pappophorum boreale, Digitaria cilliaris and Cleistogenes squrrosa began to germinate within 1-3 days after the test began, while Setaria viridis, Tragus berteronianus and Hemarthria compressa failed to germinate in a period of more than 10 days. For the species such as Digitaria cilliaris, Echinochloa hispidula, Phragmites communis, Eragrostis pilosa and Spodiopogon sibiricus, their germination period was less than 10 days, while Clinelymus dahuricus and Pappophorum boreale had a germination period of more than 20 days. The days required for half the final germination rate to be reached were: 2 days for Chloris virgata, 3 days for Phragmites communis, 4 days for Spodiopogon sibiricus, 5 days for Clinelymus dahuricus and Cleistogenes squarrosa, 7 days for Arundinella hirta and Pappophorum boreale, and 10 days for Pennisetum alopecuriodes. Compared with the Sheffield region in Britain, the Wulanaodu area of Kerqin Sandyland had a higher proportion of annul grasses with a low germination rate and a longer germination period, and the perennial grasses at the Wulanaodu area had an approximately same germination rate, but a longer germination period. During germination, ruderals showed the potential for risk-sharring, and thus, they had a relatively higher disturbance-resistance capacity.

  1. New uses of clover-grass mixtures in the structure of fodder crops on arable land

    Directory of Open Access Journals (Sweden)

    Jiří Sláma

    2010-01-01

    Full Text Available The use of clover-grasses in the structure of fodder crops grown on arable soil, especially those with intergeneric hybrids as the main component part, could avert the negative current trend, i.e. further decreasing the area of perennial fodder plants or fodder crops as a whole on arable soil. They have an irreplaceable role in crop sequences and in preserving the cultural character of the countryside, above all due to the fact that they improve soil fertility and microbial life in the soil and that they have an excellent pre-produce value, and, at the same time, they are applied in various farming systems (both conventional and ecological and in various climatic conditions, and agricultural businesses are well equipped for growing, harvesting and storing them. In the Czech Republic, the area of fodder crops grown on arable soil was decreased from 1,019.9 thousand hectares to mere 396.7 thousand hectares between 1980 and 2009, which is 15.6 % of the total area of arable soil whereas perennial fodder plants only take up 8.5 %. Fodder from clover crops and clover-grass growths on arable soil are one of the main resources of voluminous fodder for dairy cows. Most of this fodder is preserved through a fermentation process (silages, hay storage; a smaller part is fed as fresh fodder, or serves for production of hay. Silages made with perennial fodder plants are the most important source of both proteins and other nutrients for ruminants, especially for high-yielding milch cows. The basis of fodder production systems are the conservative elements of the landscape area (geomorphology in combination with the progressive elements (weather conditions, plants and human labour and relict ones, the representative of which is the soil. The fodder production systems in Europe are divided into five main fodder production zones. From this point of view, the areas where short-term clover-grass mixtures are grown on arable soil could be classed with Zone 4, i

  2. Inter-simple sequence repeat (ISSR) loci mapping in the genome of perennial ryegrass

    DEFF Research Database (Denmark)

    Pivorienė, O; Pašakinskienė, I; Brazauskas, G

    2008-01-01

    The aim of this study was to identify and characterize new ISSR markers and their loci in the genome of perennial ryegrass. A subsample of the VrnA F2 mapping family of perennial ryegrass comprising 92 individuals was used to develop a linkage map including inter-simple sequence repeat markers...... demonstrated a 70% similarity to the Hordeum vulgare germin gene GerA. Inter-SSR mapping will provide useful information for gene targeting, quantitative trait loci mapping and marker-assisted selection in perennial ryegrass....

  3. The new normal: the Canadian prairies in a changing climate

    National Research Council Canada - National Science Library

    Sauchyn, David J; Diaz, Harry P; Kulshreshtha, Surendra N

    2010-01-01

    ...-consumer recycled paper with earth friendly vegetable-based inks. Cover and text design: Duncan Campbell, CPRC. Editor for the Press: Brian Mlazgar, CPRC. cover Photos: front cover: "High angle view of snow melting in a field" by Harri Tahvanainen, Gorilla Creative/Getty Images. back cover: "Patch of grass in thawing snow" by Image Source...

  4. Influence of resource availability on Juniperus virginiana expansion in a forest–prairie ecotone

    Science.gov (United States)

    Despite being native to the United States, Juniperus virginiana has rapidly expanded in prairie ecosystems bringing detrimental ecological effects and increased wildfire risk. We transplanted J. virginiana seedlings in three plant communities to investigate mechanisms driving J. ...

  5. Anticoagulant Prairie Dog Bait Risk Mitigation Measures to Protect Endangered Species

    Science.gov (United States)

    This Web page contains information on how certified pesticide applicators can use anticoagulant prairie dog bait products such as Rozol and Kaput-D while minimizing exposure risks to listed and non-target species.

  6. Effects of N on plant response to heat-wave: a field study with prairie vegetation.

    Science.gov (United States)

    Wang, Dan; Heckathorn, Scott A; Mainali, Kumar; Hamilton, E William

    2008-11-01

    More intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic ecological impacts. Increasing nitrogen (N) availability and its dynamics will likely impact plant responses to heat stress and carbon (C) sequestration in terrestrial ecosystems. This field study examined the effects of N availability on plant response to heat-stress (HS) treatment in naturally-occurring vegetation. HS (5 d at ambient or 40.5 degrees C) and N treatments (+/-N) were applied to 16 1 m(2) plots in restored prairie vegetation dominated by Andropogon gerardii (warm-season C4 grass) and Solidago canadensis (warm-season C3 forb). Before, during, and after HS, air, canopy, and soil temperature were monitored; net CO2 assimilation (P(n)), quantum yield of photosystem II (Phi(PSII)), stomatal conductance (g(s)), and leaf water potential (Psi(w)) of the dominant species and soil respiration (R(soil)) of each plot were measured daily during HS. One week after HS, plots were harvested, and C% and N% were determined for rhizosphere and bulk soil, and above-ground tissue (green/senescent leaf, stem, and flower). Photosynthetic N-use efficiency (PNUE) and N resorption rate (NRR) were calculated. HS decreased P(n), g(s), Psi(w), and PNUE for both species, and +N treatment generally increased these variables (+/-HS), but often slowed their post-HS recovery. Aboveground biomass tended to decrease with HS in both species (and for green leaf mass in S. canadensis), but decrease with +N for A. gerardii and increase with +N for S. canadensis. For A. gerardii, HS tended to decrease N% in green tissues with +N, whereas in S. canadensis, HS increased N% in green leaves. Added N decreased NRR for A. gerardii and HS increased NRR for S. canadensis. These results suggest that heat waves, though transient, could have significant effects on plants, communities, and ecosystem N cycling, and N can influence the effect of heat waves.

  7. Repeated burning of eastern tallgrass prairie increases richness and diversity, stabilizing late successional vegetation.

    Science.gov (United States)

    Bowles, Marlin L; Jones, Michael D

    2013-03-01

    Understanding temporal effects of fire frequency on plant species diversity and vegetation structure is critical for managing tallgrass prairie (TGP), which occupies a mid-continental longitudinal precipitation and productivity gradient. Eastern TGP has contributed little information toward understanding whether vegetation-fire interactions are uniform or change across this biome. We resampled 34 fire-managed mid- and late-successional ungrazed TGP remnants occurring across a dry to wet-mesic moisture gradient in the Chicago region of Illinois, USA. We compared hypotheses that burning acts either as a stabilizing force or causes change in diversity and structure, depending upon fire frequency and successional stage. Based on western TGP, we expected a unimodal species richness distribution across a cover-productivity gradient, variable functional group responses to fire frequency, and a negative relationship between fire frequency and species richness. Species diversity was unimodal across the cover gradient and was more strongly humpbacked in stands with greater fire frequency. In support of a stabilizing hypothesis, temporal similarity of late-successional vegetation had a logarithmic relationship with increasing fire frequency, while richness and evenness remained stable. Temporal similarity within mid-successional stands was not correlated with fire frequency, while richness increased and evenness decreased over time. Functional group responses to fire frequency were variable. Summer forb richness increased under high fire frequency, while C4 grasses, spring forbs, and nitrogen-fixing species decreased with fire exclusion. On mesic and wet-mesic sites, vegetation structure measured by the ratio of woody to graminoid species was negatively correlated with abundance of forbs and with fire frequency. Our findings that species richness responds unimodally to an environmental-productivity gradient, and that fire exclusion increases woody vegetation and leads to loss

  8. The potential of perennial cave ice in isotope palaeoclimatology

    International Nuclear Information System (INIS)

    Yonge, Charles J.; MacDonald, William D.

    1999-01-01

    Perennial ice from caves on and to the east of the Canadian Great Divide yield delta O 18 and delta D values which are usually high measurements where compared with the average precipitation for the region. Furthermore, these ice data fall below and along lines of lower slope than the Global Meteoric Water Line. To explain the observed relationships, we propose the following process. a vapour-ice isotopic fractionation mechanism operates on warm season vapour when it precipitates as hoar ice on entering the caves. The subsequent fall of hoar to the cave floor through mechanical overloading along with ice derived from ground-water seepage (with a mean annual isotopic composition), results in massive ice formation of a mixed composition. This mixed composition is what is observed in the characteristic relationships found here. Such findings suggest that a warm versus cold climate interpretation for ancient cave ice may be the opposite of that found in the more familiar polar and glacial ice caves. (Author) 3 figs., 1 tab., 12 refs

  9. Modelling farmer uptake of perennial energy crops in the UK

    International Nuclear Information System (INIS)

    Sherrington, Chris; Moran, Dominic

    2010-01-01

    The UK Biomass Strategy suggests that to reach the technical potential of perennial energy crops such as short rotation coppice (SRC) willow and miscanthus by 2020 requires 350,000 hectares of land. This represents a more than 20-fold increase on the current 15,546 hectares. Previous research has identified several barriers to adoption, including concerns over security of income from contracts. In addition, farmers perceive returns from these crops to be lower than for conventional crops. This paper uses a farm-level linear programming model to investigate theoretical uptake of energy crops at different gross margins under the assumption of a profit-maximising decision maker, and in the absence of known barriers to adoption. The findings suggest that while SRC willow, at current prices, remains less competitive, returns to miscanthus should have encouraged adoption on a wider scale than at present. This highlights the importance of the barriers to adoption. Recently announced contracts for miscanthus appear to offer a significant premium to farmers in order to encourage them to grow the crops. This raises the question of whether a more cost-effective approach would be for government to provide guarantees addressing farmers concerns including security of income from the contracts. Such an approach should encourage adoption at lower gross margins. (author)

  10. BETA DIVERSITY AND COMMUNITY DIFFERENTIATION IN DRY PERENNIAL SAND GRASSLANDS

    Directory of Open Access Journals (Sweden)

    E. KOVACS-LANG

    2011-01-01

    Full Text Available The spatial variability of species composition was studied in perennial sand grasslands in Hungary at multiple scales. Three sites were compared along an aridity gradient. Existing differences in climate along this ca. 200 km gradient correspond to regional climate changes predicted for the next 20-30 years. Six stands of Festucetum vaginatae grasslands were selected at each site within 400 x 1200 m areas for representing the coarse-scale within-site heterogeneity. Fine-scale compositional heterogeneity of vegetation within stands was sampled by recording the presence of species along 52 m long circular belt transects of 1040 units of 5 cm x 5 cm contiguous microquadrats. This sampling design enabled us to study the patterns of species combinations at a wide range of scales. The highest variability of plant species combinations appeared at very fine scales, between 10 cm and 25 cm. Differences in beta diversity along the gradient were scale-dependent. We found a decreasing trend of beta diversity with increasing aridity at fine scale, and on the contrary, an increasing trend at landscape scale. We conclude that the major trend of the vegetation differentiation due to aridity is the decrease of compositional variability at fine-scale accompanied by a coarse-scale diversification.

  11. Genomic prediction in a breeding program of perennial ryegrass

    DEFF Research Database (Denmark)

    Fé, Dario; Ashraf, Bilal; Greve-Pedersen, Morten

    2015-01-01

    We present a genomic selection study performed on 1918 rye grass families (Lolium perenne L.), which were derived from a commercial breeding program at DLF-Trifolium, Denmark. Phenotypes were recorded on standard plots, across 13 years and in 6 different countries. Variants were identified...... this set. Estimated Breeding Value and prediction accuracies were calculated trough two different cross-validation schemes: (i) k-fold (k=10); (ii) leaving out one parent combination at the time, in order to test for accuracy of predicting new families. Accuracies ranged between 0.56 and 0.97 for scheme (i....... A larger set of 1791 F2s were used as training set to predict EBVs of 127 synthetic families (originated from poly-crosses between 5-11 single plants) for heading date and crown rust resistance. Prediction accuracies were 0.93 and 0.57 respectively. Results clearly demonstrate considerable potential...

  12. Impacts of mesquite distribution on seasonal space use of lesser prairie-chickens

    Science.gov (United States)

    Boggie, Matthew A.; Strong, Cody R.; Lusk, Daniel; Carleton, Scott A.; Gould, William R.; Howard, Randy L.; Nichols, Clay T.; Falkowski, Michael J.; Hagen, Christian A.

    2017-01-01

    Loss of native grasslands by anthropogenic disturbances has reduced availability and connectivity of habitat for many grassland species. A primary threat to contiguous grasslands is the encroachment of woody vegetation, which is spurred by disturbances that take on many forms from energy development, fire suppression, and grazing. These disturbances are exacerbated by natural- and human-driven cycles of changes in climate punctuated by drought and desertification conditions. Encroachment of honey mesquite (Prosopis glandulosa) into the prairies of southeastern New Mexico has potentially limited habitat for numerous grassland species, including lesser prairie-chickens (Tympanuchus pallidicinctus). To determine the magnitude of impacts of distribution of mesquite and how lesser prairie-chickens respond to mesquite presence on the landscape in southeastern New Mexico, we evaluated seasonal space use of lesser prairie-chickens in the breeding and nonbreeding seasons. We derived several remotely sensed spatial metrics to characterize the distribution of mesquite. We then used these data to create population-level resource utilization functions and predict intensity of use of lesser prairie-chickens across our study area. Home ranges were smaller in the breeding season compared with the nonbreeding season; however, habitat use was similar across seasons. During both seasons, lesser prairie-chickens used areas closer to leks and largely avoided areas with mesquite. Relative to the breeding season, during the nonbreeding season habitat use suggested a marginal increase in mesquite within areas of low intensity of use, yet aversion to mesquite was strong in areas of medium to high intensity of use. To our knowledge, our study is the first to demonstrate a negative behavioral response by lesser prairie-chickens to woody encroachment in native grasslands. To mitigate one of the possible limiting factors for lesser prairie-chickens, we suggest future conservation

  13. Widespread Use and Frequent Detection of Neonicotinoid Insecticides in Wetlands of Canada's Prairie Pothole Region

    OpenAIRE

    Main, Anson R.; Headley, John V.; Peru, Kerry M.; Michel, Nicole L.; Cessna, Allan J.; Morrissey, Christy A.

    2014-01-01

    Neonicotinoids currently dominate the insecticide market as seed treatments on Canada's major Prairie crops (e.g., canola). The potential impact to ecologically significant wetlands in this dominantly agro-environment has largely been overlooked while the distribution of use, incidence and level of contamination remains unreported. We modelled the spatial distribution of neonicotinoid use across the three Prairie Provinces in combination with temporal assessments of water and sediment concent...

  14. Social isolation induces behavioral and neuroendocrine disturbances relevant to depression in female and male prairie voles

    OpenAIRE

    Grippo, Angela J.; Gerena, Davida; Huang, Jonathan; Kumar, Narmda; Shah, Maulin; Ughreja, Raj; Carter, C. Sue

    2007-01-01

    Supportive social interactions may be protective against stressors and certain mental and physical illness, while social isolation may be a powerful stressor. Prairie voles are socially monogamous rodents that model some of the behavioral and physiological traits displayed by humans, including sensitivity to social isolation. Neuroendocrine and behavioral parameters, selected for their relevance to stress and depression, were measured in adult female and male prairie voles following 4 weeks o...

  15. Progress report: baseline monitoring of indicator species (butterflies) at tallgrass prairie restorations

    Science.gov (United States)

    Allain, Larry; Vidrine, Malcolm

    2014-01-01

    This project provides baseline data of butterfly populations at two coastal prairie restoration sites in Louisiana, the Duralde Unit of Lacassine National Wildlife Refuge (hereafter, the Duralde site) and the Cajun Prairie Restoration Project in Eunice (hereafter, the Eunice site). In all, four distinct habitat types representing different planting methods were sampled. These data will be used to assess biodiversity and health of native grasslands and also provide a basis for adaptive management.

  16. Predation of artificial ground nests on white-tailed prairie dog colonies

    Science.gov (United States)

    Baker, B.W.; Stanley, T.R.; Sedgwick, J.A.

    1999-01-01

    Prairie dog (Cynomys spp.) colonies are unique to prairie and shrub-steppe landscapes. However, widespread eradication, habitat loss, and sylvatic plague (Yersinia pestis) have reduced their numbers by 98% since historical times. Birds associated with prairie dogs also are declining. Potential nest predators, such as coyotes (Canis latrans), swift foxes (Vulpes velox), and badgers (Taxidea taxus), may be attracted to colonies where a high concentration of prairie dogs serve as available prey. Increased abundance of small mammals, including prairie dogs, also may increase the risk of predation for birds nesting on colonies. Finally, because grazing by prairie dogs may decrease vegetation height and canopy cover, bird nests may be easier for predators to locate. In this study, we placed 1,444 artificial ground nests on and off 74 white-tailed prairie dog (C. leucurus) colonies to test the hypothesis that nest predation rates are higher on colonies than at nearby off sites (i.e., uncolonized habitat). We sampled colonies from 27 May to 16 July 1997 at the following 3 complexes: Coyote Basin, Utah and Colorado; Moxa Arch, Wyoming; and Shirley Basin, Wyoming. Differences in daily predation rates between colonies and paired off sites averaged 1.0% (P = 0.060). When converted to a typical 14-day incubation period, predation rates averaged 14% higher on colonies (57.7 ?? 2.7%; ?? ?? SE) than at off sites (50.4 ?? 3.1%). Comparisons of habitat variables on colonies to off sites showed percent canopy cover of vegetation was similar (P = 0.114), percent bare ground was higher on colonies (P 0.288). Although we found the risk of nest predation was higher on white-tailed prairie dog colonies than at off sites, fitness of birds nesting on colonies might depend on other factors that influence foraging success, reproductive success, or nestling survival.

  17. Mountain plover nest survival in relation to prairie dog and fire dynamics in shortgrass steppe

    Science.gov (United States)

    Augustine, David J.; Skagen, Susan K.

    2014-01-01

    Disturbed xeric grasslands with short, sparse vegetation provide breeding habitat for mountain plovers (Charadrius montanus) across the western Great Plains. Maintaining local disturbance regimes through prairie dog conservation and prescribed fire may contribute to the sustainability of recently declining mountain plover populations, but these management approaches can be controversial. We estimated habitat-specific mountain plover densities and nest survival rates on black-tailed prairie dog (Cynomys ludovicianus) colonies and burns in the shortgrass steppe of northeastern Colorado. Mountain plover densities were similar on prairie dog colonies (5.9 birds/km2; 95% CI = 4.7–7.4) and sites burned during the preceding dormant season (6.7 birds/km2; 95% CI = 4.6–9.6), whereas the 29-day nest survival rate was greater on prairie dog colonies (0.81 in 2011 and 0.39 in 2012) compared to the burned sites (0.64 in 2011 and 0.17 in 2012). Reduced nest survival in 2012 compared to 2011 was associated with higher maximum daily temperatures in 2012, consistent with a previous weather-based model of mountain plover nest survival in the southern Great Plains. Measurements of mountain plover density relative to time since disturbance showed that removal of prairie dog disturbance by sylvatic plague reduced mountain plover density by 70% relative to active prairie dog colonies after 1 year. Plover densities declined at a similar rate (by 78%) at burned sites between the first and second post-burn growing season. Results indicate that black-tailed prairie dog colonies are a particularly important nesting habitat for mountain plovers in the southern Great Plains. In addition, findings suggest that prescribed burning can be a valuable means to create nesting habitat in landscapes where other types of disturbances (such as prairie dog colonies) are limited in distribution and size. 

  18. Wildlife habitat management on the northern prairie landscape

    Science.gov (United States)

    Johnson, Douglas H.; Haseltine, Susan D.; Cowardin, Lewis M.

    1994-01-01

    The northern prairie landscape has changed dramatically within the past century as a result of settlement by Europeans. Natural ecosystems have been disrupted and wildlife populations greatly altered. Natural resource agencies control only limited areas within the landscape, which they cannot manage independently of privately owned lands. Wildlife managers need first to set quantifiable objectives, based on the survival, reproduction, and distribution of wildlife. Second, they need to build public support and partnerships for meeting those objectives. Finally, they need to evaluate progress not only with respect to attitudes of the public and partners but, more importantly, of the wildlife response. This paper describes some useful tools for managing information at all phases of this process. We follow by discussing management options at a landscape level. Examples are given that involve agency lands as well as private lands, managed for biological resources and diversity as well as economic sustainability.

  19. Role of carbohydrate metabolism in grass tetany

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.K.; Madsen, F.C.; Lentz, D.E.; Hansard, S.L.

    1977-01-01

    Clinical hypomagnesemia is confined primarily to beef cattle in the United States but also occurs in dairy cattle in other countries, probably due to different management practices. During periods when grass tetany is likely, early vegetative temperate zone grasses are usually low in total readily available carbohydrates and magnesium but high in potassium and nitrogen. The tetany syndrome may include hypoglycemia and ketosis, suggesting an imbalance in intermediary energy metabolism. Many enzyme systems critical to cellular metabolism, including those which hydrolyze and transfer phosphate groups, are activated by Mg. Thus, by inference, Mg is required for normal glucose utilization, fat, protein, nucleic acid and coenzyme synthesis, muscle contraction, methyl group transfer, and sulfate, acetate, and formate activation. Numerous clinical and experimental studies suggest an intimate relationship between metabolism of Mg and that of carbohydrate, glucagon, and insulin. The objective is to review this literature and suggest ways in which these relationships might contribute to a chain of events leading to grass tetany.

  20. Biogas and Methane Yield from Rye Grass

    Directory of Open Access Journals (Sweden)

    Tomáš Vítěz

    2015-01-01

    Full Text Available Biogas production in the Czech Republic has expanded substantially, including marginal regions for maize cultivation. Therefore, there are increasingly sought materials that could partially replace maize silage, as a basic feedstock, while secure both biogas production and its quality.Two samples of rye grass (Lolium multiflorum var. westerwoldicum silage with different solids content 21% and 15% were measured for biogas and methane yield. Rye grass silage with solid content of 15% reached an average specific biogas yield 0.431 m3·kg−1 of organic dry matter and an average specific methane yield 0.249 m3·kg−1 of organic dry matter. Rye grass silage with solid content 21% reached an average specific biogas yield 0.654 m3·kg−1 of organic dry matter and an average specific methane yield 0.399 m3·kg−1 of organic dry matter.

  1. Rehabilitation experiment by phytoremediation using lawn grass

    International Nuclear Information System (INIS)

    2012-08-01

    Measures against environmental contamination by radioactive materials originated from the Fukushima Nuclear Accident (May, 2011), are being conducted in Fukushima and surrounding prefectures. Regarding to the measures, a phytoremediation experiment with several types of lawn grasses in a field scale have been carried out. Lawn grasses are generally characterized by shallow rhizosphere, high density and root mat formation. Decontamination effectiveness of radioactive cesium by plant uptake and by sod removing was investigated. As a result, the range of decontamination factors by plant uptake was below than 1% because of low transfer rate form soil to plant. On the other hand, maximum decontamination factor by sod removing reached about 100%. Decontamination activities with various methods will be implemented according to the national decontamination policy and related plans in each municipality. The phytoremediation method with lawn grass would be applicable in limited circumstances. (author)

  2. Classification of Prairie basins by their hysteretic connected functions

    Science.gov (United States)

    Shook, K.; Pomeroy, J. W.

    2017-12-01

    Diagnosing climate change impacts in the post-glacial landscapes of the North American Prairies through hydrological modelling is made difficult by drainage basin physiography. The region is cold, dry and flat with poorly developed stream networks, and so the basin area that is hydrologically connected to the stream outlet varies with basin depressional storage. The connected area controls the contributing area for runoff reaching the stream outlet. As depressional storage fills, ponds spill from one to another; the chain of spilling ponds allows water to flow over the landscape and increases the connected area of the basin. As depressional storage decreases, the connected fraction drops dramatically. Detailed, fine-scale models and remote sensing have shown that the relationship between connected area and the depressional storage is hysteretic in Prairie basins and that the nature of hysteresis varies with basin physiography. This hysteresis needs to be represented in hydrological models to calculate contributing area, and therefore streamflow hydrographs. Parameterisations of the hysteresis are needed for large-scale models used for climate change diagnosis. However, use of parameterisations of hysteresis requires guidance on how to represent them for a particular basin. This study shows that it is possible to relate the shape of hysteretic functions as determined by detailed models to the overall physiography of the basin, such as the fraction of the basin below the outlet, and remote sensing estimates of depressional storage, using the size distribution and location of maximum ponded water areas. By classifying basin physiography, the hysteresis of connected area - storage relationships can be estimated for basins that do not have high-resolution topographic data, and without computationally-expensive high-resolution modelling.

  3. Soils mediate the impact of fine woody debris on invasive and native grasses as whole trees are mechanically shredded into firebreaks in piñon-juniper woodlands

    Science.gov (United States)

    Aanderud, Zachary T.; Schoolmaster, Donald R.; Rigby, Deborah; Bybee, Jordon; Campbell, Tayte; Roundy, Bruce A.

    2017-01-01

    To stem wildfires, trees are being mechanically shredded into firebreaks with the resulting fine woody debris (FWD) potentially exerting immense control over soil and plants. We linked FWD-induced changes in microbial activity and nutrient availability to the frequency of Bromus tectorum and three native, perennial grasses across 31 piñon-juniper woodlands, UT, USA. Using a series of mixed models, we found that FWD increased the frequency of three of the four grasses by at least 12%. Deep, as opposed to shallow, soils mediated frequencies following FWD additions but only partially explained the variation in Bromus and Pseudoroegneria spicata. Although fertile areas associated with tree-islands elicited no response, FWD-induced increases in nitrogen mineralization in deep soils (15–17 cm) caused the frequency of the exotic and Pseudoroegneria to rise. Higher phosphorus availability in FWD-covered surface soils (0–2 cm) had no impact on grasses. FWD altered deep soil respiration, and deep and shallow microbial biomass structuring Pseudoroegneria frequencies, suggesting that microorganism themselves regulated Pseudoroegneria. The positive effects of FWD on grass frequencies intensified over time for natives but diminished for Bromus. Our results demonstrate that microorganisms in deeper soils helped mediate species-specific responses to disturbance both facilitating exotic invasion and promoting native establishment.

  4. Variation in important pasture grasses: I. Morphological and ...

    African Journals Online (AJOL)

    Variation in important pasture grasses: I. Morphological and geographical variation. ... Seven species are important pasture grasses throughout the western Transvaal, Orange Free State, northern Cape and Natal. ... Language: English.

  5. Assessment of some macromineral concentration of a grass/ legume ...

    African Journals Online (AJOL)

    Assessment of some macromineral concentration of a grass/ legume sward in ... Bulletin of Animal Health and Production in Africa ... The study aimed to determine the concentration of some macromineral elements in the grass/legume pasture ...

  6. Modelling of excess noise attnuation by grass and forest | Onuu ...

    African Journals Online (AJOL)

    , guinea grass (panicum maximum) and forest which comprises iroko (milicia ezcelea) and white afara (terminalia superba) trees in the ratio of 2:1 approximately. Excess noise attenuation spectra have been plotted for the grass and forest for ...

  7. Establishment of native and exotic grasses on mine overburden and topsoil in the Hunter Valley, New South Wales

    Energy Technology Data Exchange (ETDEWEB)

    Huxtable, C.H.A.; Koen, T.B.; Waterhouse, D. [DNR, Dangar, NSW (Australia)

    2005-07-01

    Current recommendations for rehabilitation of open-cut coal mines in the Hunter Valley involve the sowing of exotic pasture species to reinstate mined land to Class IV and V under the Rural Land Capability System. Despite the importance of native grasses in the pre-mined landscape, they are currently not widely included in mine rehabilitation. To address this issue a project was conducted between 1994 and 2000 to research the use of native grasses for rehabilitation of open-cut coal mines in the Hunter Valley. This paper reports on 2 mine site experiments that aimed to assess establishment and persistence of a broad range of native and exotic grass species from an autumn sowing in both topsoil and raw spoil over a period of 61 months. The most promising natives in terms of early establishment, persistence and spread over time, included six C-3 accessions (five Austrodanthonia spp. and Austrostipa bigeniculata) and one C-4 accession (Cynodon dactylon). Persistence of these accessions was better in raw spoil than topsoil, despite initial low numbers, due to a lack of weed competition and their ability to spread by self-seeding. In topsoil, and in the absence of any biomass reduction, native species were mostly out-competed by vigorous exotic perennial grasses which were sown in these experiments and from seed influx from adjacent rehabilitation areas or from the soil seed bank. The effects of climatic conditions and differences in soil physical, chemical and seed bank characteristics at the 2 mine sites are also discussed.

  8. Notes on Alien Bromus Grasses in Taiwan

    Directory of Open Access Journals (Sweden)

    Ming-Jer Jung

    2006-06-01

    Full Text Available Bromus carinatus Hook. & Arn., Bromus hordeaceus L., Bromus pubescens Muhl. ex Willd. and Bromus secalinus L. were recently found at middle elevations of southern and central Taiwan, respectively. We present taxonomic treatments, distribution map, and line-drawings of these introduced alien brome grasses.

  9. Notes on the nomenclature of some grasses

    NARCIS (Netherlands)

    Henrard, J.Th.

    1941-01-01

    In a former article 1) many new combinations and critical observations were published on various grasses all over the world. New investigations in critical genera together with the study of the existing literature made it necessary to accept various other arrangements in this important family. The

  10. Grass Pollen Pollution from Biofuels Farming

    Czech Academy of Sciences Publication Activity Database

    Ratajová, A.; Tříska, Jan; Vrchotová, Naděžda; Kolář, L.; Kužel, S.

    2013-01-01

    Roč. 26, č. 4 (2013), s. 199-203 ISSN 2151-321X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : grass pollen pollution * biofuels farming * temperate climate * PK-fertilization * N-fertilization * phenolic Subject RIV: EH - Ecology, Behaviour Impact factor: 0.556, year: 2013

  11. Germination of Themeda triandra (Kangaroo grass) as affected by ...

    African Journals Online (AJOL)

    Low rainfall in range areas restricts germination, growth and development of majority of range grasses. However, germination and establishment potential of forage grasses vary and depends on environmental conditions. Themeda triandra is an excellent known grass to grow under different environmental conditions.

  12. Convex relationships in ecosystems containing mixtures of trees and grass

    CSIR Research Space (South Africa)

    Scholes, RJ

    2003-12-01

    Full Text Available The relationship between grass production and the quantity of trees in mixed tree-grass ecosystems (savannas) is convex for all or most of its range. In other words, the grass production declines more steeply per unit increase in tree quantity...

  13. Names of Southern African grasses: Name changes and additional ...

    African Journals Online (AJOL)

    The main reasons for changes in botanical names are briefly reviewed, with examples from the lists. At this time, about 1040 grass species and subspecific taxa are recognized in the subcontinent. Keywords: botanical research; botanical research institute; botany; grass; grasses; identification; name change; nomenclature; ...

  14. Designing Resilient and Productive Grasses with Plasticity to Extreme Weather Events

    Science.gov (United States)

    Loka, D.; Humphreys, M.; Gwyn Jones, D.; Scullion, J.; Doonan, J.; Gasior, D.; Harper, J.; Farrell, M.; Kingston-Smith, A.; Dodd, R.; Chadwick, D.; Hill, P.; Robinson, D.; Jones, D.

    2016-12-01

    Grasslands occupy more than 70% of the world's agricultural land and are major providers of healthy feed for livestock and for ecosystem services. Global warming is projected to increase the intensity and frequency of extreme weather events such as drought and flooding and will reduce persistency of currently productive but stress sensitive forage grass varieties, thereby challenging global food security and compromising on their existing ecosystem functionality. New perennial grass varieties, tolerant to the onsets of more than one abiotic stresses, are required in order to achieve sustainable grassland production and function over years under adverse environmental conditions. Identifying and selecting reliable morphological and physiological traits associated with increased resistance to multiple stress conditions is a prerequisite to ensure future grasslands resilience. The objectives of our study were to select from diverse and novel Festulolium (ryegrass spp. x fescue spp. hybrids) grass populations capable of providing optimal combinations of good forage production together with resilience to multiple stresses and to monitor morphological and physiological responses under multiple stress conditions. The grasses were: Festulolium variety Prior (L. perenne x F. pratensis), shown to alter soil structure and hydrology to mitigate run-off and flooding; two advanced breeding populations of diploid L. perenne with genes for drought tolerance derived from the Mediterranean fescue species F. arundinacea and F. glaucescens; two tetraploid hybrid populations involving L. perenne in combination with F. glaucescens and F. mairei (from North Africa), respectively. As controls, Festulolium variety AberNiche and L. perenne variety AberWolf varieties, were used. Treatments consisted of: A) Control; plants maintained at optimum conditions, B) Flood; plants were flooded for 6 weeks followed by a 4-week recovery, C) Drought; plants received limited quantity of water for 12 weeks

  15. Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean and sorghum.

    Science.gov (United States)

    Saleh, A A; Ahmed, H U; Todd, T C; Travers, S E; Zeller, K A; Leslie, J F; Garrett, K A

    2010-01-01

    Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58% among isolates in the tallgrass prairie, 71% in the maize fields, 75% in the sorghum fields and 80% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate 'hybrids' with novel genetic profiles and pathogenic capabilities.

  16. Timing effects of heat-stress on plant physiological characteristics and growth: a field study with prairie vegetation

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2016-11-01

    Full Text Available More intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic agricultural, economic and ecological impacts. This field study examined how plant responded to heat-stress (HS treatment at different timing in naturally-occurring vegetation. HS treatment (5 days at 40.5 ºC were applied to 12 1m2 plots in restored prairie vegetation dominated by Andropogon gerardii (warm-season C4 grass and Solidago canadensis (warm-season C3 forb at different growing stages. During and after HS, air, canopy, and soil temperature were monitored; net CO2 assimilation (Pn, quantum yield of photosystem II (ФPSII, stomatal conductance (gs, and internal CO2 level (Ci of the dominant species were measured. One week after the last HS treatment, all plots were harvested and the biomass of above-ground tissue and flower weight of the two dominant species was determined. HS decreased physiological performance and growth for both species, with S. canadensis being affected more than A. gerardii, indicated by negative heat stress effect on both physiological and growth responses. There were significant timing effect of heat stress on the two species, with greater reductions in the photosynthesis and productivity occurred when heat stress was applied at later-growing season. The reduction in aboveground productivity in S. canadensis but not A. gerardii could have important implications for plant community structure by increasing the competitive advantage of A. gerardii in this grassland. The present experiment showed that heat stress, though ephemeral, may promote long-term effects on plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when more frequent and severe heat stress occur in the future.

  17. Estimating grass and grass silage degradation characteristics by in situ and in vitro gas production methods

    Directory of Open Access Journals (Sweden)

    Danijel Karolyi

    2010-01-01

    Full Text Available Fermentation characteristics of grass and grass silage at different maturities were studied using in situ and in vitro gas production methods. In situ data determined difference between grass and silage. Degradable fraction decreased as grass matured while the undegradable fraction increased. Rate of degradation (kd was slower for silage than fresh grass. Gas production method (GP data showed that fermentation of degradable fraction was different between stage of maturity in both grass and silage. Other data did not show any difference with the exception for the rate of GP of soluble and undegradable fraction. The in situ degradation characteristics were estimated from GP characteristics. The degradable and undegradable fractions could be estimated by multiple relationships. Using the three-phases model for gas production kd and fermentable organic matter could be estimated from the same parameters. The only in situ parameter that could not be estimated with GP parameters was the soluble fraction. The GP method and the three phases model provided to be an alternative to the in situ method for animal feed evaluations.

  18. A Systematic Review of Perennial Staple Crops Literature Using Topic Modeling and Bibliometric Analysis

    Science.gov (United States)

    2016-01-01

    Research on perennial staple crops has increased in the past ten years due to their potential to improve ecosystem services in agricultural systems. However, multiple past breeding efforts as well as research on traditional ratoon systems mean there is already a broad body of literature on perennial crops. In this review, we compare the development of research on perennial staple crops, including wheat, rice, rye, sorghum, and pigeon pea. We utilized the advanced search capabilities of Web of Science, Scopus, ScienceDirect, and Agricola to gather a library of 914 articles published from 1930 to the present. We analyzed the metadata in the entire library and in collections of literature on each crop to understand trends in research and publishing. In addition, we applied topic modeling to the article abstracts, a type of text analysis that identifies frequently co-occurring terms and latent topics. We found: 1.) Research on perennials is increasing overall, but individual crops have each seen periods of heightened interest and research activity; 2.) Specialist journals play an important role in supporting early research efforts. Research often begins within communities of specialists or breeders for the individual crop before transitioning to a more general scientific audience; 3.) Existing perennial agricultural systems and their domesticated crop material, such as ratoon rice systems, can provide a useful foundation for breeding efforts, accelerating the development of truly perennial crops and farming systems; 4.) Primary research is lacking for crops that are produced on a smaller scale globally, such as pigeon pea and sorghum, and on the ecosystem service benefits of perennial agricultural systems. PMID:27213283

  19. Economic and conservation implications of converting exotic forages to native warm-season grass

    Directory of Open Access Journals (Sweden)

    Adrian P. Monroe

    2017-07-01

    Full Text Available Intensive agriculture can have negative environmental consequences such as nonpoint source pollution and the simplification of biotic communities, and land sharing posits that conservation can be enhanced by integrating agricultural productivity and biodiversity on the same land. In the Southeastern United States, native warm-season grasses (NWSG may be a land sharing alternative to exotic forages currently in production because of greater livestock gains with lower fertilizer inputs, and habitat for grassland birds. However, uncertainty regarding costs and risk poses an important barrier to incorporating NWSG in livestock operations. We evaluated the economic and conservation implications of NWSG conversion among small, operational-scale pastures (6.8–10.5 ha during 2011–2012 at the Prairie Research Unit in Monroe Co., Mississippi (USA. We used partial budgets to compare the marginal rate of return (MRRe from converting exotic grass pastures to either a NWSG monoculture of Indiangrass (Sorghastrum nutans or a NWSG mix of Indiangrass, little bluestem (Schizachyrium scoparium, and big bluestem (Andropogon gerardii. We similarly compared changes in productivity of dickcissels (Spiza americana, a grassland bird specializing in tall structure. Average daily gain (ADG of steers and revenue were consistently higher for NWSG treatments than exotic grass pasture, but ADG declined between years. Indiangrass pastures yielded consistently positive MRRe, indicating producers would receive 16–24% return on investment. Marginal rate of return was lower for mixed NWSG (−12 to 3%, driven by slightly lower livestock ADG and higher establishment costs than for Indiangrass. Sensitivity analyses indicated that MRRe also was influenced by cattle selling price. Conversely, mixed NWSG increased dickcissel productivity by a greater degree than Indiangrass per amount invested in NWSG conversion, suggesting a tradeoff between livestock and dickcissel production

  20. Grass pollen immunotherapy induces highly cross-reactive IgG antibodies to group V allergen from different grass species

    NARCIS (Netherlands)

    van Ree, R.; Brewczyński, P. Z.; Tan, K. Y.; Mulder-Willems, H. J.; Widjaja, P.; Stapel, S. O.; Aalberse, R. C.; Kroon, A. M.

    1995-01-01

    Sera from two groups of patients receiving grass pollen immunotherapy were tested on IgG reactivity with group V allergen from six different grass species. One group of patients was treated with a mixture of 10 grass species, and the other with a mixture of five. Only Lolium perenne, Dactylis

  1. Energy balance and cost-benefit analysis of biogas production from perennial energy crops pretreated by wet oxidation

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Wang, Guangtao; Møller, Henrik B.

    2008-01-01

    Perennial crops need far less energy to plant, require less fertilizer and pesticides, and show a lower negative environmental impact compared with annual crops like for example corn. This makes the cultivation of perennial crops as energy crops more sustainable than the use of annual crops....... The conversion into biogas in anaerobic digestion plants shows however much lower specific methane yields for the raw perennial crops like miscanthus and willow due to their lignocellulosic structure. Without pretreatment the net energy gain is therefore lower for the perennials than for corn. When applying wet...... oxidation to the perennial crops, however, the specific methane yield increases significantly and the ratio of energy output to input and of costs to benefit for the whole chain of biomass supply and conversion into biogas becomes higher than for corn. This will make the use of perennial crops as energy...

  2. Dinosaur demise in light of their alleged perennial polar residency

    Science.gov (United States)

    Lewy, Zeev

    2017-10-01

    The end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095-1108, 1980. doi: 10.1126/science.208.44) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons

  3. The development and adoption of conservation tillage systems on the Canadian Prairies

    Directory of Open Access Journals (Sweden)

    L. Awada

    2014-03-01

    Full Text Available One of the major agricultural innovations on the Canadian Prairies over the last 40 years has been the introduction of conservation tillage (CT. Conservation tillage-a system that includes minimum and zero tillage (ZT -was introduced as an alternative to traditional (conventional tillage (TT to control soil degradation and to promote agricultural sustainability. The development and adoption of CT systems involved pioneer farmers, engineers, scientists, and farmer associations. By the end of the 1970s, CT started to take shape on the Prairies, but for a number of economic, technical, political and social reasons, the adoption of CT did not occur on any major scale before the 1990s. Today, more than 75% of the Prairie's cropland is under some form of CT with more than 50% under ZT. In this paper, the factors behind the development and adoption of conservation tillage technology on the Prairies in the period between 1930 and 2011 are reviewed. Then, some of the benefits of the adoption of CT on the Prairies are highlighted. The data show that CT and ZT became profitable for the majority of farmers during and after the 1990s, and that the increased use of CT contributed to the dramatic decrease in the area under summerfallow and to the increase in the area sown to canola and pulse crops. These changes contributed to the reduction of all forms of land degradation and to decreases in agricultural greenhouse gas (GHG emissions.

  4. Factors that affect parasitism of black-tailed prairie dogs by fleas

    Science.gov (United States)

    Eads, David A.; Hoogland, John L.

    2016-01-01

    Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that feed on vertebrate hosts. Fleas can reduce the fitness of hosts by interfering with immune responses, disrupting adaptive behaviors, and transmitting pathogens. The negative effects of fleas on hosts are usually most pronounced when fleas attain high densities. In lab studies, fleas desiccate and die under dry conditions, suggesting that populations of fleas will tend to decline when precipitation is scarce under natural conditions. To test this hypothesis, we compared precipitation vs. parasitism of black-tailed prairie dogs (Cynomys ludovicianus) by fleas at a single colony during May and June of 13 consecutive years (1976–1988) at Wind Cave National Park, South Dakota, USA. The number of fleas on prairie dogs decreased with increasing precipitation during both the prior growing season (April through August of the prior year) and the just-completed winter–spring (January through April of current year). Due to the reduction in available moisture and palatable forage in dry years, herbivorous prairie dogs might have been food-limited, with weakened behavioral and immunological defenses against fleas. In support of this hypothesis, adult prairie dogs of low mass harbored more fleas than heavier adults. Our results have implications for the spread of plague, an introduced bacterial disease, transmitted by fleas, that devastates prairie dog colonies and, in doing so, can transform grassland ecosystems.

  5. A proposal to conserve black-footed ferrets and the prairie dog ecosystem

    Science.gov (United States)

    Miller, Brian; Wemmer, Christen; Biggins, Dean; Reading, Richard

    1990-11-01

    Prairie dogs ( Cynomys spp.) have been poisoned throughout this century because of grazing competition with livestock. Recent evidence showed these early claims were exaggerated, but animal control was already entrenched in government policy. As a result, ongoing government subsidized poisoning has reduced prairie dogs to about 2% of their former distribution. The reduction of prairie dogs diminished species diversity in the arid grasslands of North America, including the potential extinction of the black-footed ferret ( Mustela nigripes). Cost-benefit analysis revealed that poisoning costs more than any grazing benefits accrued. This analysis did not consider the long-term costs of reversing ecosystem degradation, the intangible value of biological diversity as a public benefit, or the depletion of biotic resources as a loss of actual or potential wealth. The government presently finances the poisoning policy and the preservation of endangered species like the black-footed ferret, two apparently conflicting programs. We, therefore, propose an integrated management plan that considers both interests. We propose that federal monies allocated to the poisoning program be converted into a rebate for ranchers who manage livestock while preserving the prairie dog community. This would redirect funds and personnel already allocated to prairie dog eradication to an incentive for ranchers who manage for livestock and wildlife. Livestock interests and grassland biotic diversity would both benefit.

  6. Effects of sexual dimorphism and landscape composition on the trophic behavior of Greater Prairie-Chicken.

    Directory of Open Access Journals (Sweden)

    Beatriz Blanco-Fontao

    Full Text Available Partitioning of ecological niche is expected in lekking species that show marked sexual size dimorphism as a consequence of sex-specific ecological constraints. However, niche partitioning is uncertain in species with moderate sexual dimorphism. In addition, the ecological niche of a species may also be affected by landscape composition; particularly, agricultural fragmentation may greatly influence the trophic behavior of herbivores. We studied trophic niche variation in Greater Prairie-Chickens (Tympanuchus cupido, a grouse species that shows moderate sex-dimorphism. Greater Prairie-Chickens are native to tallgrass prairies of North America, although populations persist in less natural mosaics of cropland and native habitats. We used stable isotope analysis of carbon and nitrogen in blood, claws and feathers to assess seasonal differences in trophic niche breadth and individual specialization between male and female Greater Prairie-Chickens, and between birds living in continuous and fragmented landscapes. We found that females showed broader niches and higher individual specialization than males, especially in winter and autumn. However, differences between females and males were smaller in spring when birds converge at leks, suggesting that females and males may exhibit similar feeding behaviors during the lekking period. In addition, we found that birds living in native prairies showed greater annual trophic variability than conspecifics in agricultural mosaic landscapes. Native habitats may provide greater dietary diversity, resulting in greater diversity of feeding strategies.

  7. Trichostatin A (TSA) facilitates formation of partner preference in male prairie voles (Microtus ochrogaster).

    Science.gov (United States)

    Duclot, F; Wang, H; Youssef, C; Liu, Y; Wang, Z; Kabbaj, M

    2016-05-01

    In the socially monogamous prairie voles (Microtus ochrogaster), the development of a social bonding is indicated by the formation of partner preference, which involves a variety of environmental and neurochemical factors and brain structures. In a most recent study in female prairie voles, we found that treatment with the histone deacetylase inhibitor trichostatin A (TSA) facilitates the formation of partner preference through up-regulation of oxytocin receptor (OTR) and vasopressin V1a receptor (V1aR) genes expression in the nucleus accumbens (NAcc). In the present study, we tested the hypothesis that TSA treatment also facilitates partner preference formation and alters OTR and V1aR genes expression in the NAcc in male prairie voles. We thus observed that central injection of TSA dose-dependently promoted the formation of partner preference in the absence of mating in male prairie voles. Interestingly, TSA treatment up-regulated OTR, but not V1aR, gene expression in the NAcc similarly as they were affected by mating - an essential process for naturally occurring partner preference. These data, together with others, not only indicate the involvement of epigenetic events but also the potential role of NAcc oxytocin in the regulation of partner preference in both male and female prairie voles. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Assessment of lesser prairie-chicken use of wildlife water guzzlers

    Science.gov (United States)

    Boal, Clint W.; Borsdorf, Philip K.; Gicklhorn, Trevor S.

    2014-01-01

    Man-made water sources have been used as a management tool for wildlife, especially in arid regions, but the value of these water sources for wildlife populations is not well understood. In particular, the value of water as a conservation tool for Lesser Prairie-Chickens (Tympanuchus pallidicinctus) is unknown. However, this is a relevant issue due to a heightened conservation concern for the species and its occupancy of an arid landscape anticipated to experience warmer, drier springs and winters. We assessed if Lesser Prairie-Chickens would use commercially available wildlife water guzzlers and if there was any apparent selection between two design types. We confirmed that Lesser Prairie-Chickens would use bird friendly designed wildlife water guzzlers. Use was primarily during the lekking-nesting period (March–May) and the brood rearing period (June–July) and primarily by males. Although both designs were used, we found significantly greater use of a design that had a wider water trough and ramp built into the tank cover compared to a design that had a longer, narrower trough extending from the tank.Although we were unable to assess the physiological need of surface water by Lesser Prairie-Chickens, we were able to verify that they will use wildlife water guzzlers to access surface water. If it is found surface water is beneficial for Lesser Prairie-Chickens, game bird friendly designed guzzlers may be a useful conservation tool for the species.

  9. Hydrology of prairie wetlands: Understanding the integrated surface-water and groundwater processes

    Science.gov (United States)

    Hayashi, Masaki; van der Kamp, Garth; Rosenberry, Donald O.

    2016-01-01

    Wetland managers and policy makers need to make decisions based on a sound scientific understanding of hydrological and ecological functions of wetlands. This article presents an overview of the hydrology of prairie wetlands intended for managers, policy makers, and researchers new to this field (e.g., graduate students), and a quantitative conceptual framework for understanding the hydrological functions of prairie wetlands and their responses to changes in climate and land use. The existence of prairie wetlands in the semi-arid environment of the Prairie-Pothole Region (PPR) depends on the lateral inputs of runoff water from their catchments because mean annual potential evaporation exceeds precipitation in the PPR. Therefore, it is critically important to consider wetlands and catchments as highly integrated hydrological units. The water balance of individual wetlands is strongly influenced by runoff from the catchment and the exchange of groundwater between the central pond and its moist margin. Land-use practices in the catchment have a sensitive effect on runoff and hence the water balance. Surface and subsurface storage and connectivity among individual wetlands controls the diversity of pond permanence within a wetland complex, resulting in a variety of eco-hydrological functionalities necessary for maintaining the integrity of prairie-wetland ecosystems.

  10. Nowcasting daily minimum air and grass temperature

    Science.gov (United States)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  11. A comparative study of AMF diversity in annual and perennial plant species from semiarid gypsum soils.

    Science.gov (United States)

    Alguacil, M. M.; Torrecillas, E.; Roldán, A.; Díaz, G.; Torres, P.

    2012-04-01

    The arbuscular mycorrhizal fungi (AMF) communities composition regulate plant interactions and determine the structure of plant communities. In this study we analysed the diversity of AMF in the roots of two perennial gypsophyte plant species, Herniaria fruticosa and Senecio auricula, and an annual herbaceous species, Bromus rubens, growing in a gypsum soil from a semiarid area. The objective was to determine whether perennial and annual host plants support different AMF communities in their roots and whether there are AMF species that might be indicators of specific functional plant roles in these ecosystems. The roots were analysed by nested PCR, cloning, sequencing of the ribosomal DNA small subunit region and phylogenetic analysis. Twenty AMF sequence types, belonging to the Glomus group A, Glomus group B, Diversisporaceae, Acaulosporaceae, Archaeosporaceae and Paraglomeraceae, were identified. Both gypsophyte perennial species had differing compositions of the AMF community and higher diversity when compared with the annual species, showing preferential selection by specific AMF sequences types. B. rubens did not show host specificity, sharing the full composition of its AMF community with both perennial plant species. Seasonal variations in the competitiveness of AM fungi could explain the observed differences in AMF community composition, but this is still a working hypothesis that requires the analysis of further data obtained from a higher number of both annual and perennial plant species in order to be fully tested.

  12. Students' Perceptions of a Highly Controversial yet Keystone Species, the Black-Tailed Prairie Dog: A Case Study

    Science.gov (United States)

    Fox-Parrish, Lynne; Jurin, Richard R.

    2008-01-01

    The authors used a case-study methodology to explore the perceptions of 30 9th-grade biology students relative to black-tailed prairie dogs. The case study, which involved classroom- and field-based experiences that focused on black-tailed prairie dogs, revealed 3 major themes: apathy, egocentrism, and naive conceptions. The authors had hoped that…

  13. Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

    Science.gov (United States)

    M.A. Callaham; J.M. Blair; T.C. Todd; D.J. Kitchen; M.R. Whiles

    2003-01-01

    The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups. and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station. we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term...

  14. 75 FR 70021 - South Dakota Prairie Winds Project; Partial Term Relinquishment and Release of Easement for Wind...

    Science.gov (United States)

    2010-11-16

    ... requested financing for the project from the RUS. PW SD1 has also submitted an application to the Service to...] South Dakota Prairie Winds Project; Partial Term Relinquishment and Release of Easement for Wind Energy... impact statement (FEIS) on the South Dakota Prairie Winds Project issued by the Department of Energy's...

  15. Validity of accessible critical nitrogen dilution curves in perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Gislum, René; Boelt, Birte

    2009-01-01

    The objectives were to test if accessible critical nitrogen dilution curves (NDCs) in rapeseed, pea, alfalfa, tall fescue, wheat, annual ryegrass and linseed could be used in grass species for seed production and to develop a critical NDC especially in grass species for seed production. The criti......The objectives were to test if accessible critical nitrogen dilution curves (NDCs) in rapeseed, pea, alfalfa, tall fescue, wheat, annual ryegrass and linseed could be used in grass species for seed production and to develop a critical NDC especially in grass species for seed production...... the NDCs in tall fescue, alfalfa, pea and rapeseed. These findings should be used to continue the interesting and necessary work on developing a NDC in grass species for seed production....

  16. Social recognition is context dependent in single male prairie voles

    Science.gov (United States)

    Zheng, Da-Jiang; Foley, Lauren; Rehman, Asad; Ophir, Alexander G.

    2013-01-01

    Single males might benefit from knowing the identity of neighbouring males when establishing and defending boundaries. Similarly, males should discriminate between individual females if this leads to more reproductive opportunities. Contextual social cues may alter the value of learning identity. Knowing the identity of competitors that intrude into an animal’s territory may be more salient than knowing the identity of individuals on whose territory an animal is trespassing. Hence, social and environmental context could affect social recognition in many ways. Here we test social recognition of socially monogamous single male prairie voles, Microtus ochrogaster. In experiment 1 we tested recognition of male or female conspecifics and found that males discriminated between different males but not between different females. In experiment 2 we asked whether recognition of males is influenced when males are tested in their own cage (familiar), in a clean cage (neutral) or in the home cage of another male (unfamiliar). Although focal males discriminated between male conspecifics in all three contexts, individual variation in recognition was lower when males were tested in their home cage (in the presence of familiar social cues) compared to when the context lacked social cues (neutral). Experiment 1 indicates that selective pressures may have operated to enhance male territorial behaviour and indiscriminate mate selection. Experiment 2 suggests that the presence of a conspecific cue heightens social recognition and that home-field advantages might extend to social cognition. Taken together, our results indicate social recognition depends on the social and possibly territorial context. PMID:24273328

  17. Climate impacts on the hydrology of prairie wetlands

    International Nuclear Information System (INIS)

    Woo, Mingko; Rowsell, R.D.

    1991-01-01

    A study was carried out in the St. Denis National Wildlife Area, 45 km east of Saskatoon, to observe the hydrological processes and the temporal and spatial variability of slough responses to climate. One slough was instrumented for detailed study, showing that the high water level in spring was supported by snowmelt. In summer, rainfall was the major source of water supply, but was exceeded by losses to evaporation and groundwater recharge, leading to a decline of the water table and complete drying by June 13th. The duration that water remains in sloughs varies temporally and spatially. Ephemeral sloughs, deriving water mainly from snowmelt, tend to occupy higher ground, temporary sloughs rely on precipitation and surface runoff, and may receive groundwater discharge during wetter years. Permanent sloughs often occupy lower areas, receiving water from precipitation, lateral runoff, and groundwater discharge which buffers them from year to year fluctuations in precipitation. Tree ring analyses showed that meltwater is the major factor influencing tree growth, correlating the spatial variability of slough inundation to the temporal variability of winter snowfall. A study of slough hydrology is important to the understanding of the responses of Prairie wetlands to climatic variability and change. 17 refs., 2 figs

  18. Managing Water-Food-Energy Futures in the Canadian Prairies

    Science.gov (United States)

    Wheater, H. S.; Hassanzadeh, E.; Nazemi, A.; Elshorbagy, A. A.

    2016-12-01

    The water-food-energy nexus is a convenient phrase to highlight competing societal uses for water and the need for cross-sectoral policy integration, but this can lead to oversimplification of the multiple dimensions of water (and energy) management. In practice, water managers must balance (and prioritize) demands for water for many uses, including environmental flows, and reservoir operation often involves managing conflicting demands, for example to maximize retention for supply, reduce storage to facilitate flood control, and constrain water levels and releases for habitat protection. Agriculture and water quality are also inextricably linked: irrigated agriculture requires appropriate water quality for product quality and certification, but agriculture can be a major source of nutrient pollution, with impacts on human and ecosystem health, drinking water treatment and amenity. And energy-water interactions include energy production (hydropower and cooling water for thermal power generation) and energy consumption (e.g. for pumping and water and wastewater treatment). These dependencies are illustrated for the Canadian prairies, and a risk-based approach to the management of climate change is presented. Trade-offs between economic benefits of hydropower and irrigation are illustrated for alternative climate futures, including implications for freshwater habitats. The results illustrate that inter-sector interactions vary as a function of climate and its variability, and that there is a need for policy to manage inter-sector allocations as a function of economic risk.

  19. Assessing diversity of prairie plants using remote sensing

    Science.gov (United States)

    Gamon, J. A.; Wang, R.

    2017-12-01

    Biodiversity loss endangers ecosystem services and is considered as a global change that may generate unacceptable environmental consequences for the Earth system. Global biodiversity observations are needed to provide a better understanding of biodiversity - ecosystem services relationships and to provide a stronger foundation for conserving the Earth's biodiversity. While remote sensing metrics have been applied to estimate α biodiversity directly through optical diversity, a better understanding of the mechanisms behind the optical diversity-biodiversity relationship is needed. We designed a series of experiments at Cedar Creek Ecosystem Science Reserve, MN, to investigate the scale dependence of optical diversity and explore how species richness, evenness, and composition affect optical diversity. We collected hyperspectral reflectance of 16 prairie species using both a full-range field spectrometer fitted with a leaf clip, and an imaging spectrometer carried by a tram system to simulate plot-level images with different species richness, evenness, and composition. Two indicators of spectral diversity were explored: the coefficient of variation (CV) of spectral reflectance in space, and spectral classification using a Partial Least Squares Discriminant Analysis (PLS-DA). Our results showed that sampling methods (leaf clip-derived data vs. image-derived data) affected the optical diversity estimation. Both optical diversity indices were affected by species richness and evenness (Pguide regional studies of biodiversity estimation using high spatial and spectral resolution remote sensing.

  20. Map of mixed prairie grassland vegetation, Rocky Flats, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Clark, S J.V.; Webber, P J; Komarkova, V; Weber, W A

    1980-01-01

    A color vegetation map at the scale of 1:12,000 of the area surrounding the Rocky Flats, Rockwell International Plant near Boulder, Colorado, provides a permanent record of baseline data which can be used to monitor changes in both vegetation and environment and thus to contribute to future land management and land-use policies. Sixteen mapping units based on species composition were identified, and characterized by two 10-m/sup 2/ vegetation stands each. These were grouped into prairie, pasture, and valley side on the basis of their species composition. Both the mapping units and these major groups were later confirmed by agglomerative clustering analysis of the 32 vegetation stands on the basis of species composition. A modified Bray and Curtis ordination was used to determine the environmental factor complexes controlling the distribution of vegetation at Rocky flats. Recommendations are made for future policies of environmental management and predictions of the response to environmental change of the present vegetation at the Rocky Flats site.