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Sample records for grassland endemic passerine

  1. Nocturnal activity of nesting shrubland and grassland passerines: Chapter 9

    Science.gov (United States)

    Slay, Christy M.; Ellison, Kevin S.; Ribic, Christine; Smith, Kimberly G.; Schmitz, Carolyn M.

    2013-01-01

    Nocturnal activity of nesting passerines is largely undocumented in field situations. We used video recordings to quantify sleep patterns of four shrubland and three grassland bird species during the nestling period. All species exhibited “back sleep” (bill tucked under scapular feathers); individuals woke frequently for vigils of their surroundings. Sleep-bout duration varied from 6 minutes (grasshopper sparrow) to 28 minutes (blue-winged warbler, field sparrow). Duration on nest varied from 6.4 hours (field sparrow) to 8.8 hours (indigo bunting). Adults woke 20–30 minutes before sunrise. First morning absence from the nest was short; nestlings were fed within 12 minutes of a parent’s departure. Further research is needed to understand energetic costs of sleep and behavioral adaptations to environmental pressures.

  2. A 'slow pace of life' in Australian old-endemic passerine birds is not accompanied by low basal metabolic rates.

    Science.gov (United States)

    Bech, Claus; Chappell, Mark A; Astheimer, Lee B; Londoño, Gustavo A; Buttemer, William A

    2016-05-01

    Life history theory suggests that species experiencing high extrinsic mortality rates allocate more resources toward reproduction relative to self-maintenance and reach maturity earlier ('fast pace of life') than those having greater life expectancy and reproducing at a lower rate ('slow pace of life'). Among birds, many studies have shown that tropical species have a slower pace of life than temperate-breeding species. The pace of life has been hypothesized to affect metabolism and, as predicted, tropical birds have lower basal metabolic rates (BMR) than temperate-breeding birds. However, many temperate-breeding Australian passerines belong to lineages that evolved in Australia and share 'slow' life-history traits that are typical of tropical birds. We obtained BMR from 30 of these 'old-endemics' and ten sympatric species of more recently arrived passerine lineages (derived from Afro-Asian origins or introduced by Europeans) with 'faster' life histories. The BMR of 'slow' temperate-breeding old-endemics was indistinguishable from that of new-arrivals and was not lower than the BMR of 'fast' temperate-breeding non-Australian passerines. Old-endemics had substantially smaller clutches and longer maximal life spans in the wild than new arrivals, but neither clutch size nor maximum life span was correlated with BMR. Our results suggest that low BMR in tropical birds is not functionally linked to their 'slow pace of life' and instead may be a consequence of differences in annual thermal conditions experienced by tropical versus temperate species.

  3. New phytotoxic diterpenoids from Vellozia gigantea (Velloziaceae), an endemic neotropical plant living in the endangered Brazilian biome Rupestrian grasslands

    Science.gov (United States)

    Vellozia gigantea is a rare, ancient and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera and Lemna paucicostata, and showed larvicidal activity against ...

  4. Nest Success and Cause-Specific Nest Failure of Grassland Passerines Breeding in Prairie Grazed by Livestock

    Science.gov (United States)

    This manuscript describes two years of field research on ground-nesting songbird species at Zumwalt Prairie Reserve, northeastern Oregon, USA. Cattle-grazing has long been suspected in declines of ground-nesting songbirds in grazed grassland, primarily due to increased trampling...

  5. Relatively high prevalence of pox-like lesions in Henslow's sparrow (Ammodrammus henslowii) among nine species of migratory grassland passerines in Wisconsin, USA.

    Science.gov (United States)

    Ellison, Kevin S; Hofmeister, Erik K; Ribic, Christine A; Sample, David W

    2014-10-01

    Globally, Avipoxvirus species affect over 230 species of wild birds and can significantly impair survival. During banding of nine grassland songbird species (n=346 individuals) in southwestern Wisconsin, USA, we noted species with a 2-6% prevalence of pox-like lesions (possible evidence of current infection) and 4-10% missing digits (potential evidence of past infection). These prevalences approach those recorded among island endemic birds (4-9% and 9-20% for the Galapagos and Hawaii, respectively) for which Avipoxvirus species have been implicated as contributing to dramatic population declines. Henslow's Sparrow Ammodramus henslowii (n=165 individuals) had the highest prevalence of lesions (6.1%) and missing digits (9.7%). Among a subset of 26 Henslow's Sparrows from which blood samples were obtained, none had detectable antibody reactive to fowlpox virus antigen. However, four samples (18%) had antibody to canarypox virus antigen with test sample and negative control ratios (P/N values) ranging from 2.4 to 6.5 (median 4.3). Of four antibody-positive birds, two had lesions recorded (one was also missing a digit), one had digits missing, and one had no signs. Additionally, the birds with lesions or missing digits had higher P/N values than did the antibody-positive bird without missing digits or recorded lesions. This study represents an impetus for considering the impacts and dynamics of disease caused by Avipoxvirus among North American grassland bird species.

  6. Relatively high prevalence of pox-like lesions in Henslow's Sparrow (Ammodramus henslowii) among nine species of migratory grassland passerines in Wisconsin, USA

    Science.gov (United States)

    Ellison, Kevin S.; Hofmeister, Erik K.; Ribic, Christine A.; Sample, David W.

    2014-01-01

    Globally, Avipoxvirus species affect over 230 species of wild birds and can significantly impair survival. During banding of nine grassland songbird species (n = 346 individuals) in southwestern Wisconsin, USA, we noted species with a 2–6% prevalence of pox-like lesions (possible evidence of current infection) and 4–10% missing digits (potential evidence of past infection). These prevalences approach those recorded among island endemic birds (4–9% and 9–20% for the Galapagos and Hawaii, respectively) for which Avipoxvirus species have been implicated as contributing to dramatic population declines. Henslow's Sparrow Ammodramus henslowii (n = 165 individuals) had the highest prevalence of lesions (6.1%) and missing digits (9.7%). Among a subset of 26 Henslow's Sparrows from which blood samples were obtained, none had detectable antibody reactive to fowlpox virus antigen. However, four samples (18%) had antibody to canarypox virus antigen with test sample and negative control ratios (P/N values) ranging from 2.4 to 6.5 (median 4.3). Of four antibody-positive birds, two had lesions recorded (one was also missing a digit), one had digits missing, and one had no signs. Additionally, the birds with lesions or missing digits had higher P/N values than did the antibody-positive bird without missing digits or recorded lesions. This study represents an impetus for considering the impacts and dynamics of disease caused by Avipoxvirus among North American grassland bird species.

  7. New Pesticidal Diterpenoids from Vellozia gigantea (Velloziaceae, an Endemic Neotropical Plant Living in the Endangered Brazilian Biome Rupestrian Grasslands

    Directory of Open Access Journals (Sweden)

    Mariana C. Ferreira

    2017-01-01

    Full Text Available Vellozia gigantea is a rare, ancient, and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera, and Lemna paucicostata, and showed larvicidal activity against Aedes aegypti. Phytotoxicity bioassay-directed fractionation of the extract revealed one new isopimaradiene, 8(9,15-isopimaradien-1,3,7,11-tetraone, and three new cleistanthane diterpenoids, 7-oxo-8,11,13-cleistanthatrien-3-ol, 3,20-epoxy-7-oxo-8,11,13-cleistanthatrien-3-ol, and 20-nor-3,7-dioxo-1,8,11,13-cleistanthatetraen-10-ol. These new structures are proposed based on interpretation of 1H, 13C, COSY, NOESY, HSQC, and HMBC NMR data. 8(9,15-isopimaradien-1,3,7,11-tetraone was especially phytotoxic with an IC50 value (30 μM comparable to those of commercial herbicides clomazone, EPTC, and naptalam. In addition, 7-oxo-8,11,13-cleistanthatrien-3-ol provided 100% mortality at a concentration of 125 ppm against one-day-old Ae. aegypti larvae. Our results show that ancient and unique plants, like the endangered narrowly endemic neotropical species V. gigantea present in the Rupestrian grasslands, should also be protected because they can be sources of new bioactive compounds.

  8. Nectar robbing in Collaea cipoensis (Fabaceae), an endemic shrub of the Brazilian rupestrian grasslands

    OpenAIRE

    Gelvez-Zúñiga, Irene; Aguirre, Armando; Martén-Rodríguez, Silvana; Matos-Gomes, Vanessa; Barbosa, Arleu; Bordignon, Leandra; Rocha, Rosana; Fernandes, Geraldo W.

    2016-01-01

    Abstract: Nectar robbery is common in flowering plants with tubular corollas and can affect plant reproductive success. Our study characterized the interaction between potential pollinators and nectar robbers, and assessed the effects on flower abortion in a population of the restricted endemic Collaea cipoensis (Fabaceae) at Serra do Cipó, Brazil. We conducted observations of floral visitors to identify potential pollinators from nectar robbers and described visitor behavior. We also analyze...

  9. Late Pleistocene songbirds of Liang Bua (Flores, Indonesia); the first fossil passerine fauna described from Wallacea

    Science.gov (United States)

    Sutikna, Thomas; Saptomo, Wahyu; Jatmiko; Wasisto, Sri; Tocheri, Matthew W.; Mayr, Gerald

    2017-01-01

    Background Passerines (Aves: Passeriformes) dominate modern terrestrial bird communities yet their fossil record is limited. Liang Bua is a large cave on the Indonesian island of Flores that preserves Late Pleistocene–Holocene deposits (∼190 ka to present day). Birds are the most diverse faunal group at Liang Bua and are present throughout the stratigraphic sequence. Methods We examined avian remains from the Late Pleistocene deposits of Sector XII, a 2 × 2 m area excavated to about 8.5 m depth. Although postcranial passerine remains are typically challenging to identify, we found several humeral characters particularly useful in discriminating between groups, and identified 89 skeletal elements of passerines. Results At least eight species from eight families are represented, including the Large-billed Crow (Corvus cf. macrorhynchos), the Australasian Bushlark (Mirafra javanica), a friarbird (Philemon sp.), and the Pechora Pipit (Anthus cf. gustavi). Discussion These remains constitute the first sample of fossil passerines described in Wallacea. Two of the taxa no longer occur on Flores today; a large sturnid (cf. Acridotheres) and a grassbird (Megalurus sp.). Palaeoecologically, the songbird assemblage suggests open grassland and tall forests, which is consistent with conditions inferred from the non-passerine fauna at the site. Corvus cf. macrorhynchos, found in the Homo floresiensis-bearing layers, was likely part of a scavenging guild that fed on carcasses of Stegodon florensis insularis alongside vultures (Trigonoceps sp.), giant storks (Leptoptilos robustus), komodo dragons (Varanus komodoensis), and probably H. floresiensis as well. PMID:28828271

  10. Late Pleistocene songbirds of Liang Bua (Flores, Indonesia; the first fossil passerine fauna described from Wallacea

    Directory of Open Access Journals (Sweden)

    Hanneke J.M. Meijer

    2017-08-01

    Full Text Available Background Passerines (Aves: Passeriformes dominate modern terrestrial bird communities yet their fossil record is limited. Liang Bua is a large cave on the Indonesian island of Flores that preserves Late Pleistocene–Holocene deposits (∼190 ka to present day. Birds are the most diverse faunal group at Liang Bua and are present throughout the stratigraphic sequence. Methods We examined avian remains from the Late Pleistocene deposits of Sector XII, a 2 × 2 m area excavated to about 8.5 m depth. Although postcranial passerine remains are typically challenging to identify, we found several humeral characters particularly useful in discriminating between groups, and identified 89 skeletal elements of passerines. Results At least eight species from eight families are represented, including the Large-billed Crow (Corvus cf. macrorhynchos, the Australasian Bushlark (Mirafra javanica, a friarbird (Philemon sp., and the Pechora Pipit (Anthus cf. gustavi. Discussion These remains constitute the first sample of fossil passerines described in Wallacea. Two of the taxa no longer occur on Flores today; a large sturnid (cf. Acridotheres and a grassbird (Megalurus sp.. Palaeoecologically, the songbird assemblage suggests open grassland and tall forests, which is consistent with conditions inferred from the non-passerine fauna at the site. Corvus cf. macrorhynchos, found in the Homo floresiensis-bearing layers, was likely part of a scavenging guild that fed on carcasses of Stegodon florensis insularis alongside vultures (Trigonoceps sp., giant storks (Leptoptilos robustus, komodo dragons (Varanus komodoensis, and probably H. floresiensis as well.

  11. Effects of wind turbines on upland nesting birds in Conservation Reserve Program grasslands

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    Leddy, K.L.; Higgins, K.F.; Naugle, D.E.

    1999-01-01

    Grassland passerines were surveyed during summer 1995 on the Buffalo Ridge Wind Resource Area in southwestern Minnesota to determine the relative influence of wind turbines on overall densities of upland nesting birds in Conservation Reserve Program (CRP) grasslands. Birds were surveyed along 40 m fixed width transects that were placed along wind turbine strings within three CRP fields and in three CRP fields without turbines. Conservation Reserve Program grasslands without turbines and areas located 180 m from turbines supported higher densities (261.0-312.5 males/100 ha) of grassland birds than areas within 80 m of turbines (58.2-128.0 males/100 ha). Human disturbance, turbine noise, and physical movements of turbines during operation may have disturbed nesting birds. We recommend that wind turbines be placed within cropland habitats that support lower densities of grassland passerines than those found in CRP grasslands.

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

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    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

  13. Grassland Sustainability

    Science.gov (United States)

    Deborah U. Potter; Paulette L. Ford

    2004-01-01

    In this chapter we discuss grassland sustainability in the Southwest, grassland management for sustainability, national and local criteria and indicators of sustainable grassland ecosystems, and monitoring for sustainability at various scales. Ecological sustainability is defined as: [T]he maintenance or restoration of the composition, structure, and processes of...

  14. Some conservation aspects of papyrus endemic passerines around ...

    African Journals Online (AJOL)

    Scopus: Journal of East African Ornithology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 28 (2008) >. Log in or Register to get access to full text downloads.

  15. Avian disease assessment in seabirds and non-native passerines birds at Midway Atoll NWR

    Science.gov (United States)

    LaPointe, Dennis A.; Atkinson, Carter T.; Klavitter, John L.

    2013-01-01

    Midway Atoll in the Northwestern Hawaiian Islands supports the largest breeding colony of Laysan albatross (Phoebastria immutabilis) in the world and is a proposed site for the translocation of endangered Northwestern Hawaiian Island passerine birds such as the Nihoa finch (Telespiza ultima), Nihoa millerbird (Acrocephalus familiaris kingi), or Laysan finch (Telespiza cantans). On the main Hawaiian Islands, introduced mosquito-borne avian malaria (Plasmodium relictum) and avian pox (Avipoxvirus) have contributed to the extinction and decline of native Hawaiian avifauna. The mosquito vector (Culex quinquefasciatus) is present on Sand Island, Midway Atoll, where epizootics of Avipoxvirus have been reported among nestling Laysan albatross, black-footed albatross (Phoebastria nigripes), and red-tailed tropicbirds (Phaethon rubricauda) since 1963. Two introduced passerines, the common canary (Serinus canaria) and the common myna (Acridotheres tristis), are also present on Sand Island and may serve as reservoirs of mosquito-borne pathogens. Assessing disease prevalence and transmission potential at Midway Atoll National Wildlife Refuge (NWR) is a critical first step to translocation of Nihoa endemic passerines. In May 2010 and April 2012 we surveyed Midway Atoll NWR for mosquitoes and evidence of mosquito-borne disease. Although we did not observe active pox infections on albatross nestlings in May 2010, active infections were prevalent on albatross nestlings in April 2012. Presumptive diagnosis of Avipoxvirus was confirmed by PCR amplification of the Avipoxvirus 4b core protein gene from lesions collected from 10 albatross nestlings. Products were sequenced and compared to 4b core protein sequences from 28 Avipoxvirus isolates from the Hawaiian Islands and other parts of the world. Sequences from all Midway isolates were identical and formed a clade with other Avipoxvirus isolates from seabirds that was distinct from other Avipoxvirus isolates from the Hawaiian Islands

  16. Ecology, reproductive biology and conservation of Picris willkommii (Schultz Bip.) Nyman (Asteraceae): an endemic, protected species from therophytic grasslands of South-Western Iberian Peninsula; Ecologia, biologia reproductiva y conservacion de Picris willkommii (Schultz Bip.) Nyman (Asteraceae): endemismo protegido integrado en pastos terofiticos del suroeste de la Peninsula Iberica

    Energy Technology Data Exchange (ETDEWEB)

    Monteagudo Sanchez-Movellan, F. J.; Butler Sierra, I.; Bastida Milian, F.

    2009-07-01

    Current knowledge of the biology of Picris willkommii and his grade of threat, seem not to be sufficient to ensure long term persistence of this plant species endemic to the South-Western Iberian Peninsula. In Spain, main populations of the species are narrowly restricted to therophytic grasslands around the town of Ayamonte, by the Guadiana river drainage. Results of the present study indicate that P. willkommii behaves as a very versatile, colonizing species in most of the habitats of their natural range, where it appears to be well suited to the cyclic disturbance dynamics imposed by local, traditional land uses, i.e. extensive rain-fed agriculture. Moreover, it is easy to grow under controlled conditions. Results could be helpful for conservation and population recovery purposes, as recent changes in land use, shifting from agricultural traditional systems to urban expansion or alternative agricultural systems, pose at risk P. willkommii populations due to habitat loss. (Author) 35 refs.

  17. Passerine morphology: external measurements of approximately one-quarter of passerine bird species.

    Science.gov (United States)

    Ricklefs, Robert E

    2017-05-01

    Studies of community organization and clade diversification that include functional traits have become an important component of the analysis of ecological and evolved systems. Such studies frequently are limited by availability of consistently collected data. Here, I present a data set including eight measurements of the external morphology of 1642 species, roughly one-quarter of all passerine birds (Aves: Order Passeriformes), from all parts of the world, characterizing the relative proportions of the wing, tail, legs, and beak. Specimens were measured opportunistically over the past 40 years in museums in the United States and Europe. Numbers of individuals measured per species vary from one to dozens in some cases. Measurements for males and females of sexually size-dimorphic species are presented separately. The measurements include total length, the lengths of the wing, tail, tarsus, and middle toe, and the length, breadth, and depth of the beak. Particular attention was paid to obtaining a broad representation of passerine higher taxa, with special interest in small families and subfamilies of passerines, as well as species produced by evolutionary radiations of birds in archipelagoes, including the Galapagos, Hawaii, and the Lesser Antilles. Taxonomy follows the Taxonomy in Flux (TIF) checklist as well as the World Bird List of the International Ornithological Council. Geographic distributions are summarized from Edwards's Coded List of Birds of the World. Coverage of taxa and geographic regions varies and reflects the changing interests of the author over the past four decades. North American and South American species are particularly well represented in the sample, as well as species belonging to the families Tyrannidae, Furnariidae, Thamnophilidae, Mimidae, Sturnidae, Fringillidae, Parulidae, Icteridae, Cardinalidae, and Thraupidae. © 2017 by the Ecological Society of America.

  18. Extremes of heat, drought and precipitation depress reproductive performance in shortgrass prairie passerines

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    Conrey, Reesa Y.; Skagen, Susan K.; Yackel, Amy; Panjabi, Arvind O.

    2016-01-01

    Climate change elevates conservation concerns worldwide because it is likely to exacerbate many identified threats to animal populations. In recent decades, grassland birds have declined faster than other North American bird species, a loss thought to be due to habitat loss and fragmentation and changing agricultural practices. Climate change poses additional threats of unknown magnitude to these already declining populations. We examined how seasonal and daily weather conditions over 10 years influenced nest survival of five species of insectivorous passerines native to the shortgrass prairie and evaluate our findings relative to future climate predictions for this region. Daily nest survival (n = 870) was best predicted by a combination of daily and seasonal weather variables, age of nest, time in season and bird habitat guild. Within a season, survival rates were lower on very hot days (temperatures ≥ 35 °C), on dry days (with a lag of 1 day) and on stormy days (especially for those species nesting in shorter vegetation). Across years, survival rates were also lower during warmer and drier breeding seasons. Clutch sizes were larger when early spring temperatures were cool and the week prior to egg-laying was wetter and warming. Climate change is likely to exacerbate grassland bird population declines because projected climate conditions include rising temperatures, more prolonged drought and more intense storms as the hydrological cycle is altered. Under varying realistic scenarios, nest success estimates were halved compared to their current average value when models both increased the temperature (3 °C) and decreased precipitation (two additional dry days during a nesting period), thus underscoring a sense of urgency in identifying and addressing the current causes of range-wide declines.

  19. Daytime passerine migrants over the Sahara — are these diurnal ...

    African Journals Online (AJOL)

    The landing tendency (sink rate) correlated negatively with the tail wind component. Transect counts on the ground revealed very low proportions of diurnal migrants, not matching the relatively high densities of passerine migration during the day, and a high correlation between transect density of nocturnal migrants and ...

  20. Ticks (Ixodidae) from passerine birds in the Carpathian region

    Czech Academy of Sciences Publication Activity Database

    Spitalska, E.; Literák, I.; Sparagano, O. A .E.; Golovchenko, Maryna; Kocianová, E.

    2006-01-01

    Roč. 118, 23/24 (2006), 759-764 ISSN 0043-5325 Institutional research plan: CEZ:AV0Z60220518 Keywords : Passerine birds * Ixodes ricinus * Borrelia * Rickettsia * Ehrlichia * Carpathians Subject RIV: EC - Immunology Impact factor: 0.804, year: 2006

  1. Agonistic behaviour of Palaearctic passerine migrants at a stopover ...

    African Journals Online (AJOL)

    We recorded intraspecific and interspecific interactions of Palaearctic migrant passerine birds at Ouadâne, Mauritania, a stopover site in the Sahara desert. ... our observations suggest interspecific interference competition because inferior individuals are temporarily deprived of food, which may influence the fitness of ...

  2. Insect diet of some afrotropical insectivorous passerines at the Jos ...

    African Journals Online (AJOL)

    Despite being the most common avian dietary strategy, our understanding of the nutrition of avian insectivores lags behind that of less populous granivores, herbivores, and frugivores; thereby attracting research interest. Insect diet of Afrotropical insectivorous passerines at the Jos Wildlife Park was studied by trapping birds ...

  3. The California Valley grassland

    Science.gov (United States)

    Keeley, J.E.; Schoenherr, Allan A.

    1990-01-01

    Grasslands are distributed throughout California from Oregon to Baja California Norte and from the coast to the desert (Brown 1982) (Figure 1). This review will focus on the dominant formation in cismontane California, a community referred to as Valley Grassland (Munz 1959). Today, Valley Grassland is dominated by non-native annual grasses in genera such as Avena (wild oat), Bromus (brome grass), and Hordeum (barley), and is often referred to as the California annual grassland. On localized sites, native perennial bunchgrasses such as Stipa pultra (purple needle grass) may dominate and such sites are interpreted to be remnants of the pristine valley grassland. In northwestern California a floristically distinct formation of the Valley Grassland, known as Coast Prairie (Munz 1959) or Northern Coastal Grassland (Holland and Keil 1989) is recognized. The dominant grasses include many native perennial bunchgrasses in genera such as Agrostis, Calamagrostis, Danthonia, Deschampsia, Festuca, Koeleria and Poa (Heady et al. 1977). Non-native annuals do not dominate, but on some sites non-native perennials like Anthoxanthum odoratum may colonize the native grassland (Foin and Hektner 1986). Elevationally, California's grasslands extend from sea level to at leas 1500 m. The upper boundary is vague because montane grassland formations are commonly referred to as meadows; a community which Munz (1959) does not recognize. Holland and Keil (1989) describe the montane meadow as an azonal community; that is, a community restricted not so much to a particular climatic zone but rather controlled by substrate characteristics. They consider poor soil-drainage an over-riding factor in the development of montane meadows and, in contrast to grasslands, meadows often remain green through the summer drought. Floristically, meadows are composed of graminoids; Cyperaceae, Juncaceae, and rhizomatous grasses such as Agropyron (wheat grass). Some bunchgrasses, such as Muhlenbergia rigens, are

  4. Nest-site selection and nest success of an Arctic-breeding passerine, Smith's Longspur, in a changing climate

    Science.gov (United States)

    McFarland, Heather R.; Kendall, Steve J.; Powell, Abby

    2017-01-01

    Despite changes in shrub cover and weather patterns associated with climate change in the Arctic, little is known about the breeding requirements of most passerines tied to northern regions. We investigated the nesting biology and nest habitat characteristics of Smith's Longspurs (Calcarius pictus) in 2 study areas in the Brooks Range of Alaska, USA. First, we examined variation in nesting phenology in relation to local temperatures. We then characterized nesting habitat and analyzed nest-site selection for a subset of nests (n = 86) in comparison with paired random points. Finally, we estimated the daily survival rate of 257 nests found in 2007–2013 with respect to both habitat characteristics and weather variables. Nest initiation was delayed in years with snow events, heavy rain, and freezing temperatures early in the breeding season. Nests were typically found in open, low-shrub tundra, and never among tall shrubs (mean shrub height at nests = 26.8 ± 6.7 cm). We observed weak nest-site selection patterns. Considering the similarity between nest sites and paired random points, coupled with the unique social mating system of Smith's Longspurs, we suggest that habitat selection may occur at the neighborhood scale and not at the nest-site scale. The best approximating model explaining nest survival suggested a positive relationship with the numbers of days above 21°C that an individual nest experienced; there was little support for models containing habitat variables. The daily nest survival rate was high (0.972–0.982) compared with that of most passerines in forested or grassland habitats, but similar to that of passerines nesting on tundra. Considering their high nesting success and ability to delay nest initiation during inclement weather, Smith's Longspurs may be resilient to predicted changes in weather regimes on the breeding grounds. Thus, the greatest threat to breeding Smith's Longspurs associated with climate change may be the loss of low

  5. Going to extremes: contrasting rates of diversification in a recent radiation of new world passerine birds.

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    Barker, F Keith; Burns, Kevin J; Klicka, John; Lanyon, Scott M; Lovette, Irby J

    2013-03-01

    Recent analyses suggest that a few major shifts in diversification rate may be enough to explain most of the disparity in diversity among vertebrate lineages. At least one significant increase in diversification rate appears to have occurred within the birds; however, several nested lineages within birds have been identified as hyperdiverse by different studies. A clade containing the finches and relatives (within the avian order Passeriformes), including a large radiation endemic to the New World that comprises ~8% of all bird species, may be the true driver of this rate increase. Understanding the patterns and processes of diversification of this diverse lineage may go a long way toward explaining the apparently rapid diversification rates of both passerines and of birds as a whole. We present the first multilocus phylogenetic analyses of this endemic New World radiation of finch relatives that include sampling of all recognized genera, a relaxed molecular clock analysis of its divergence history, and an analysis of its broad-scale diversification patterns. These analyses recovered 5 major lineages traditionally recognized as avian families, but identified an additional 10 relatively ancient lineages worthy of recognition at the family level. Time-calibrated diversification analyses suggested that at least 3 of the 15 family-level lineages were significantly species poor given the entire group's background diversification rate, whereas at least one-the tanagers of family Thraupidae-appeared significantly more diverse. Lack of an age-diversity relationship within this clade suggests that, due to rapid initial speciation, it may have experienced density-dependent ecological limits on its overall diversity.

  6. Open cup nests evolved from roofed nests in the early passerines.

    Science.gov (United States)

    Price, J Jordan; Griffith, Simon C

    2017-02-08

    The architectural diversity of nests in the passerine birds (order Passeriformes) is thought to have played an important role in the adaptive radiation of this group, which now comprises more than half of avian species and occupies nearly all terrestrial ecosystems. Here, we present an extensive survey and ancestral state reconstruction of nest design across the passerines, focusing on early Australian lineages and including members of nearly all passerine families worldwide. Most passerines build open cup-shaped nests, whereas a minority build more elaborate domed structures with roofs. We provide strong evidence that, despite their relative rarity today, domed nests were constructed by the common ancestor of all modern passerines. Open cup nests evolved from enclosed domes at least four times independently during early passerine evolution, at least three of which occurred on the Australian continent, yielding several primarily cup-nesting clades that are now widespread and numerically dominant among passerines. Our results show that the ubiquitous and relatively simple cup-shaped nests of many birds today evolved multiple times convergently, suggesting adaptive benefits over earlier roofed designs. © 2017 The Author(s).

  7. Passerine bird communities of Iberian dehesas: a review

    Directory of Open Access Journals (Sweden)

    Tellería, J. L.

    2001-01-01

    Full Text Available The Iberian dehesas are a man-made habitat composed of scattered oaks (Quercus spp. and extensive grass cover occupying three million ha in south-western Iberia. This paper compares the structure of the passerine bird communities in this region with other bird assemblages of Iberian woodlands. Although forest bird numbers in the southern half of the Iberian peninsula are decreasing, the dehesas show the highest richness in breeding birds, seemingly as the result of the increased presence of border and open-habitat birds. A low intra-habitat turnover of species was observed in the dehesas, with birds recorded at a sampling point accounting for a high percentage of the total richness of the community. This can be related to the low spatial patchiness of this habitat. In winter, the dehesas continued to maintain many bird species, but showed bird densities similar to other woodlands. This pattern, as well as the scarcity of some common forest passerines during the breeding period, could result from the removal of the shrub layer typical of Mediterranean woodlands.

  8. Coccidia in passerines from the Nevado de Toluca National Park, Mexico.

    Science.gov (United States)

    Medina, Juan P; Salgado-Miranda, Celene; García-Conejo, Michele; Galindo-Sánchez, Karla P; Mejía-García, Cristian J; Janczur, Mariusz K; Gomes Lopes, Carlos W; Berto, Bruno P; Soriano-Vargas, Edgardo

    2014-03-01

    In this study, we found unsporulated coccidia oocysts in passerines from the Nevado de Toluca National Park, Mexico. We captured birds and took samples of their droppings during three field visits. We examined a total of 72 fecal samples and found unsporulated coccidia oocysts in 10 samples from five passerine species: Atlapetes pileatus (3), Cardelina ruber (1), Mniotilta varia (1), Oreothlypis celata (2) and Regulus calendula (3). This appears to be the first recorded study of unsporulated coccidia oocysts in passerine species from Mexico.

  9. Genomic analysis of $\\textit{Salmonella enterica}$ serovar Typhimurium from wild passerines in England and Wales

    OpenAIRE

    Mather, Alison E; Lawson, Becki; de, Pinna Elizabeth; Wigley, Paul; Parkhill, Julian; Thomson, Nicholas R; Page, Andrew J; Holmes, Mark Adrian; Paterson, Gavin K

    2016-01-01

    Passerine salmonellosis is a well-recognised disease of birds in the order Passeriformes, including common songbirds such as finches and sparrows, caused by infection with $\\textit{Salmonella enterica}$ serovar Typhimurium. Previous research has suggested that some subtypes of S. Typhimurium – definitive phage types (DT) 40, 56 variant, and 160 – are host-adapted to passerines, and that these birds may represent a reservoir of infection for humans and other animals. Here, we have used whole g...

  10. Insect ectoparasites from wild passerine birds in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Sychra O.

    2008-12-01

    Full Text Available Wild passerine birds (Passeriformes from northeastern part of the Czech Republic were examined for ectoparasites. Three species of louse-flies of the genus Ornithomya (Diptera: Hippoboscidae, two species of fleas of the genera Ceratophyllus and Dasypsyllus (Siphonaptera: Ceratophyllidae, and 15 species of chewing lice belonging to the genera Myrsidea, Menacanthus (Phthiraptera: Menoponidae, Brueelia, Penenirmus, Philopterus (Phthiraptera: Philopteridae were found on 82 birds of 23 species. New chewing louse-host records are Hippolais icterina for Menacanthus currucae; Motacilla cinerea for Menacanthus pusillus; Turdus philomelos and Motacilla cinerea for Brueelia merulensis; and Sylvia atricapilla for Menacanthus eurysternus. Brueelia neoatricapillae is cited for the first time for the Czech Republic. Parasitological parameters such as prevalence, intensity and abundance are also discussed.

  11. Passerine birds breeding under chronic noise experience reduced fitness.

    Directory of Open Access Journals (Sweden)

    Julia Schroeder

    Full Text Available BACKGROUND: Fitness in birds has been shown to be negatively associated with anthropogenic noise, but the underlying mechanisms remain obscure. It is however crucial to understand the mechanisms of how urban noise impinges on fitness to obtain a better understanding of the role of chronic noise in urban ecology. Here, we examine three hypotheses on how noise might reduce reproductive output in passerine birds: (H1 by impairing mate choice, (H2 by reducing territory quality and (H3 by impeding chick development. METHODOLOGY/PRINCIPAL FINDINGS: We used long-term data from an island population of house sparrows, Passer domesticus, in which we can precisely estimate fitness. We found that nests in an area affected by the noise from large generators produced fewer young, of lower body mass, and fewer recruits, even when we corrected statistically for parental genetic quality using a cross-fostering set-up, supporting H3. Also, individual females provided their young with food less often when they bred in the noisy area compared to breeding attempts by the same females elsewhere. Furthermore, we show that females reacted flexibly to increased noise levels by adjusting their provisioning rate in the short term, which suggests that noise may be a causal factor that reduces reproductive output. We rejected H1 and H2 because nestbox occupancy, parental body mass, age and reproductive investment did not differ significantly between noisy and quiet areas. CONCLUSIONS/SIGNIFICANCE: OUR RESULTS SUGGEST A PREVIOUSLY UNDESCRIBED MECHANISM TO EXPLAIN HOW ENVIRONMENTAL NOISE CAN REDUCE FITNESS IN PASSERINE BIRDS: by acoustically masking parent-offspring communication. More importantly, using a cross-fostering set-up, our results demonstrate that birds breeding in a noisy environment experience significant fitness costs. Chronic noise is omnipresent around human habitation and may produces similar fitness consequences in a wide range of urban bird species.

  12. Grassland biodiversity can pay.

    Science.gov (United States)

    Binder, Seth; Isbell, Forest; Polasky, Stephen; Catford, Jane A; Tilman, David

    2018-04-10

    The biodiversity-ecosystem functioning (BEF) literature provides strong evidence of the biophysical basis for the potential profitability of greater diversity but does not address questions of optimal management. BEF studies typically focus on the ecosystem outputs produced by randomly assembled communities that only differ in their biodiversity levels, measured by indices such as species richness. Landholders, however, do not randomly select species to plant; they choose particular species that collectively maximize profits. As such, their interest is not in comparing the average performance of randomly assembled communities at each level of biodiversity but rather comparing the best-performing communities at each diversity level. Assessing the best-performing mixture requires detailed accounting of species' identities and relative abundances. It also requires accounting for the financial cost of individual species' seeds, and the economic value of changes in the quality, quantity, and variability of the species' collective output-something that existing multifunctionality indices fail to do. This study presents an assessment approach that integrates the relevant factors into a single, coherent framework. It uses ecological production functions to inform an economic model consistent with the utility-maximizing decisions of a potentially risk-averse private landowner. We demonstrate the salience and applicability of the framework using data from an experimental grassland to estimate production relationships for hay and carbon storage. For that case, our results suggest that even a risk-neutral, profit-maximizing landowner would favor a highly diverse mix of species, with optimal species richness falling between the low levels currently found in commercial grasslands and the high levels found in natural grasslands.

  13. The genetic effects of Late Quaternary climatic changes over a tropical latitudinal gradient: diversification of an Atlantic Forest passerine.

    Science.gov (United States)

    d'Horta, Fernando M; Cabanne, Gustavo S; Meyer, Diogo; Miyaki, Cristina Y

    2011-05-01

    The increase in biodiversity from high to low latitudes is a widely recognized biogeographical pattern. According to the latitudinal gradient hypothesis (LGH), this pattern was shaped by differential effects of Late Quaternary climatic changes across a latitudinal gradient. Here, we evaluate the effects of climatic changes across a tropical latitudinal gradient and its implications to diversification of an Atlantic Forest (AF) endemic passerine. We studied the intraspecific diversification and historical demography of Sclerurus scansor, based on mitochondrial (ND2, ND3 and cytb) and nuclear (FIB7) gene sequences. Phylogenetic analyses recovered three well-supported clades associated with distinct latitudinal zones. Coalescent-based methods were applied to estimate divergence times and changes in effective population sizes. Estimates of divergence times indicate that intraspecific diversification took place during Middle-Late Pleistocene. Distinct demographic scenarios were identified, with the southern lineage exhibiting a clear signature of demographic expansion, while the central one remained more stable. The northern lineage, contrasting with LGH predictions, exhibited a clear sign of a recent bottleneck. Our results suggest that different AF regions reacted distinctly, even in opposite ways, under the same climatic period, producing simultaneously favourable scenarios for isolation and contact among populations. © 2011 Blackwell Publishing Ltd.

  14. A phylogenetic hypothesis for passerine birds: taxonomic and biogeographic implications of an analysis of nuclear DNA sequence data.

    Science.gov (United States)

    Barker, F Keith; Barrowclough, George F; Groth, Jeff G

    2002-02-07

    Passerine birds comprise over half of avian diversity, but have proved difficult to classify. Despite a long history of work on this group, no comprehensive hypothesis of passerine family-level relationships was available until recent analyses of DNA-DNA hybridization data. Unfortunately, given the value of such a hypothesis in comparative studies of passerine ecology and behaviour, the DNA-hybridization results have not been well tested using independent data and analytical approaches. Therefore, we analysed nucleotide sequence variation at the nuclear RAG-1 and c-mos genes from 69 passerine taxa, including representatives of most currently recognized families. In contradiction to previous DNA-hybridization studies, our analyses suggest paraphyly of suboscine passerines because the suboscine New Zealand wren Acanthisitta was found to be sister to all other passerines. Additionally, we reconstructed the parvorder Corvida as a basal paraphyletic grade within the oscine passerines. Finally, we found strong evidence that several family-level taxa are misplaced in the hybridization results, including the Alaudidae, Irenidae, and Melanocharitidae. The hypothesis of relationships we present here suggests that the oscine passerines arose on the Australian continental plate while it was isolated by oceanic barriers and that a major northern radiation of oscines (i.e. the parvorder Passerida) originated subsequent to dispersal from the south.

  15. Chromosomal inversion differences correlate with range overlap in passerine birds.

    Science.gov (United States)

    Hooper, Daniel M; Price, Trevor D

    2017-10-01

    Chromosomal inversions evolve frequently but the reasons for this remain unclear. We used cytological descriptions of 411 species of passerine birds to identify large pericentric inversion differences between species, based on the position of the centromere. Within 81 small clades comprising 284 of the species, we found 319 differences on the 9 largest autosomes combined, 56 on the Z chromosome, and 55 on the W chromosome. We also identified inversions present within 32 species. Using a new fossil-calibrated phylogeny, we examined the phylogenetic, demographic and genomic context in which these inversions have evolved. The number of inversion differences between closely related species is consistently predicted by whether the ranges of species overlap, even when time is controlled for as far as is possible. Fixation rates vary across the autosomes, but inversions are more likely to be fixed on the Z chromosome than the average autosome. Variable mutagenic input alone (estimated by chromosome size, map length, GC content or repeat density) cannot explain the differences between chromosomes in the number of inversions fixed. Together, these results support a model in which inversions increase because of their effects on recombination suppression in the face of hybridization. Other factors associated with hybridization may also contribute, including the possibility that inversions contain incompatibility alleles, making taxa less likely to collapse following secondary contact.

  16. A supermatrix phylogeny of corvoid passerine birds (Aves: Corvides).

    Science.gov (United States)

    Jønsson, Knud Andreas; Fabre, Pierre-Henri; Kennedy, Jonathan D; Holt, Ben G; Borregaard, Michael K; Rahbek, Carsten; Fjeldså, Jon

    2016-01-01

    The Corvides (previously referred to as the core Corvoidea) are a morphologically diverse clade of passerine birds comprising nearly 800 species. The group originated some 30 million years ago in the proto-Papuan archipelago, to the north of Australia, from where lineages have dispersed and colonized all of the world's major continental and insular landmasses (except Antarctica). During the last decade multiple species-level phylogenies have been generated for individual corvoid families and more recently the inter-familial relationships have been resolved, based on phylogenetic analyses using multiple nuclear loci. In the current study we analyse eight nuclear and four mitochondrial loci to generate a dated phylogeny for the majority of corvoid species. This phylogeny includes 667 out of 780 species (85.5%), 141 out of 143 genera (98.6%) and all 31 currently recognized families, thus providing a baseline for comprehensive macroecological, macroevolutionary and biogeographical analyses. Using this phylogeny we assess the temporal consistency of the current taxonomic classification of families and genera. By adopting an approach that enforces temporal consistency by causing the fewest possible taxonomic changes to currently recognized families and genera, we find the current familial classification to be largely temporally consistent, whereas that of genera is not. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Nest predation and reproductive traits in small passerines: a comparative approach

    Science.gov (United States)

    Yanes, Miguel; Suárez, Francisco

    Nest predation can be a decisive factor in the evolution of bird reproduction strategies. This paper compares several reproductive traits in small passerines on the Iberian Peninsula (n=31) with the probability of daily nest survival from predation. We consider the phylogenetic relationships between species by means of an analysis according to three models of evolutionary change: Brownian, punctuational and GRAFEN'S arbitrary. In this comparative evolutionary scenario, clutch size, egg volume and incubation period appear not to change in relation to nest predation, while the nestling phase duration is a positively-related parameter to daily nest survival from predation. These results are consistent for all models of evolutionary change. Thus, from the perspective of nest predation, the nestling period is the most important evolutionary parameter in small passerines. A hypothetical influence of nest predation on passerine clutch and egg size should only be regarded as an indirect factor, linked to the relationship between these parameters and the duration of the nestling period.

  18. Macroevolution of life-history traits in passerine birds: adaptation and phylogenetic inertia.

    Science.gov (United States)

    Pienaar, Jason; Ilany, Amiyaal; Geffen, Eli; Yom-Tov, Yoram

    2013-05-01

    We used a recent passerine phylogeny and comparative method to evaluate the macroevolution of body and egg mass, incubation and fledging periods, time to independence and time with parents of the main passerine lineages. We hypothesised that passerine reproductive traits are affected by adaptation to both past and present environmental factors and phenotypic attributes such as body mass. Our results suggest that the evolution of body and egg mass, time to independence, incubation and fledging times are affected by strong phylogenetic inertia and that these breeding traits are all affected by body mass. Time with parents, where major lineages exhibit their own fixed optima and body mass does not have an effect, and clutch size which is affected by body mass and additionally by climate regimes, do not exhibit any phylogenetic inertia. © 2013 Blackwell Publishing Ltd/CNRS.

  19. Multiple Weather Factors Affect Apparent Survival of European Passerine Birds

    Science.gov (United States)

    Salewski, Volker; Hochachka, Wesley M.; Fiedler, Wolfgang

    2013-01-01

    Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for

  20. Physiological effects of increased foraging effort in a small passerine.

    Science.gov (United States)

    Yap, Kang Nian; Kim, Oh Run; Harris, Karilyn C; Williams, Tony D

    2017-11-15

    Foraging to obtain food, either for self-maintenance or at presumably elevated rates to provide for offspring, is thought to be an energetically demanding activity but one that is essential for fitness (higher reproductive success and survival). Nevertheless, the physiological mechanisms that allow some individuals to support higher foraging performance, and the mechanisms underlying costs of high workload, remain poorly understood. We experimentally manipulated foraging behaviour in zebra finches ( Taeniopygia guttata ) using the technique described by Koetsier and Verhulst (2011) Birds in the 'high foraging effort' (HF) group had to obtain food either while flying/hovering or by making repeated hops or jumps from the ground up to the feeder, behaviour typical of the extremely energetically expensive foraging mode observed in many free-living small passerines. HF birds made significantly more trips to the feeder per 10 min, whereas control birds spent more time (perched) at the feeder. Despite this marked change in foraging behaviour, we documented few short- or long-term effects of 'training' (3 days and 90 days of 'training', respectively) and some of these effects were sex specific. There were no effects of treatment on basal metabolic rate, haematocrit, haemoglobin or plasma glycerol, triglyceride and glucose levels, and masses of kidney, crop, large intestine, small intestine, gizzard and liver. HF females had higher masses of flight muscle, leg muscle, heart and lung compared with controls. In contrast, HF males had lower heart mass than controls and there were no differences for other organs. When both sexes were pooled, there were no effects of treatment on body composition. Finally, birds in the HF treatment group had higher levels of reactive oxygen metabolites (dROMs) and, consequently, although treatment did not affect total anti-oxidant capacity, birds in the HF treatment group had higher oxidative stress. © 2017. Published by The Company of

  1. The Pollination Ecology of an Assemblage of Grassland Asclepiads in South Africa

    OpenAIRE

    OLLERTON, JEFF; JOHNSON, STEVEN D.; CRANMER, LOUISE; KELLIE, SAM

    2003-01-01

    The KwaZulu‐Natal region of South Africa hosts a large diversity of asclepiads (Apocynaceae: Asclepiadoideae), many of which are endemic to the area. The asclepiads are of particular interest because of their characteristically highly evolved floral morphology. During 3 months of fieldwork (November 2000 to January 2001) the flower visitors and pollinators to an assemblage of nine asclepiads at an upland grassland site were studied. These observations were augmented by laboratory studies of f...

  2. Protecting Mongolia's grassland steppes | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... windy grassland region is severely damaged, desertification can quickly set in. ... to marketing to the sound use of (grassland) resources," explains Ykhanbai, who ... is going to require improvement in the skills of researchers, adds Ykhanbai.

  3. Decline in snail abundance due to soil acidification causes eggshell defects in forest passerines

    NARCIS (Netherlands)

    Graveland, J; vanderWal, R

    On poor soils in the Netherlands an increasing number of great tits, Parus major, and of other forest passerines produce eggs with defective shells and have low reproductive success as a result of calcium deficiency. A similar increase in eggshell defects has been observed in Germany and Sweden.

  4. Decline in snail abundance due to soil acidification causes eggshell defects in forest passerines

    NARCIS (Netherlands)

    Graveland, J.; Van der Wal, R.

    1996-01-01

    On poor soils in the Netherlands an increasing number of great tits, Parus major, and of other forest passerines produce eggs with defective shells and have low reproductive success as a result of calcium deficiency. A similar increase in eggshell defects has been observed in Germany and Sweden.

  5. Factors determining presence of passerines breeding within White Stork Ciconia ciconia nests.

    Science.gov (United States)

    Zbyryt, Adam; Jakubas, Dariusz; Tobolka, Marcin

    2017-08-18

    Nests of White Stork Ciconia ciconia are commonly used by various passerines as nesting sites. In this study, we investigated factors determining presence and number of pairs of species breeding within White Stork nests in an extensive farmland in NE Poland. In 133 (57%) out of 233 White Stork nests, we found at least one breeding pair of passerine bird. These were from three species: House Sparrows Passer domesticus (68% of 133 nests with co-breeding), Tree Sparrows Passer montanus (65%), and Starlings Sturnus vulgaris (30%). The probability of breeding passerines within White Stork nests increased with increasing nest thickness, and was significantly higher in currently occupied nests. Sparrows were more likely to breed in White Stork nests located on electricity poles, situated closer to settlements and surrounded mainly by arable fields where meadows were not prevalent. In this paper, we show that White Stork nests are favorable nesting sites for passerines, as they are well insulated and provide an anti-predatory shield.

  6. Factors determining presence of passerines breeding within White Stork Ciconia ciconia nests

    Science.gov (United States)

    Zbyryt, Adam; Jakubas, Dariusz; Tobolka, Marcin

    2017-10-01

    Nests of White Stork Ciconia ciconia are commonly used by various passerines as nesting sites. In this study, we investigated factors determining presence and number of pairs of species breeding within White Stork nests in an extensive farmland in NE Poland. In 133 (57%) out of 233 White Stork nests, we found at least one breeding pair of passerine bird. These were from three species: House Sparrows Passer domesticus (68% of 133 nests with co-breeding), Tree Sparrows Passer montanus (65%), and Starlings Sturnus vulgaris (30%). The probability of breeding passerines within White Stork nests increased with increasing nest thickness, and was significantly higher in currently occupied nests. Sparrows were more likely to breed in White Stork nests located on electricity poles, situated closer to settlements and surrounded mainly by arable fields where meadows were not prevalent. In this paper, we show that White Stork nests are favorable nesting sites for passerines, as they are well insulated and provide an anti-predatory shield.

  7. Age ratios and their possible use in determining autumn routes of passerine migrants

    Science.gov (United States)

    C. John Ralph

    1981-01-01

    Age ratios and abundance of 61 migrant passerine species comprising more than 42,000 birds were analyzed in an attempt to determine patterns of migration. The data were collected at 10 stations from coastal Massachusetts to inland Pennsylvania. Age ratios are thought to be useful in determining routes of migration. The principal criteria for the edge of a species...

  8. Predictors of extinction risk of passerine birds in a Central European country

    Czech Academy of Sciences Publication Activity Database

    Koleček, Jaroslav; Albrecht, Tomáš; Reif, J.

    2014-01-01

    Roč. 17, č. 5 (2014), s. 498-506 ISSN 1367-9430 Institutional support: RVO:68081766 Keywords : red list * life history * habitat specialization * distribution * climate change * threatened species * extinction risk * passerine Subject RIV: EG - Zoology Impact factor: 2.852, year: 2014

  9. Appreciation of grassland functions by European stakeholders

    NARCIS (Netherlands)

    Pol, van den A.; Golinski, P.; Hennessy, D.; Huyghe, C.; Parente, G.; Peyraud, J.L.

    2014-01-01

    In order to promote sustainable and competitive ruminant production systems, the European Multisward project was aimed at improving farmer trust in grassland and grassland mixtures. A questionnaire on grassland functions was submitted in eight languages, in order to better understand the importance

  10. The effects of prey size on diet differentiation of seven passerine species at two spring stopover sites

    NARCIS (Netherlands)

    Marchetti, C.M.; Locatelli, D.P.; Van Noordwijk, A.J.; Baldaccini, N.E.

    1998-01-01

    Prey size was evaluated for seven passerine trans-Saharan migrant species at two spring stopover sites in Sardinia, Italy. The species considered were Pied Flycatcher Ficedula hypoleuca, Spotted Flycatcher Muscicapa striata, Redstart Phoenicurus phoenicurus, Garden Warbler Sylvia borin, Whitethroat

  11. Monitoring in South African grasslands

    CSIR Research Space (South Africa)

    Mentis, MT

    1984-12-01

    Full Text Available The main purpose of this document is to propose how ecological monitoring might be developed in the Grassland Biome of South Africa. Monitoring is defined as the maintenance of regular surveillance to test the null hypothesis of no change...

  12. Research on the Mechanism of Cross Regional Grassland Ecological Compensation

    Science.gov (United States)

    Yang, Ran; Ma, Jun

    2018-01-01

    In recent years, grassland environmental damage has become serious, and grassland resources protection task has become heavy, grassland ecological compensation has become an effective way to solve this problem; but the current grassland ecological compensation standards were low, the effect is poor. The fundamental reason is the model of administrative division destroys the integrity of grassland. Based on the analysis of the status quo of grassland compensation, this paper tries to protect the grassland integrity, breaks the administrative division restriction, implements the space regulation, constructs the framework of cross-regional grassland ecological compensation mechanism, describes its operation process. It provides new way to realize the sustainable development of the grassland environment.

  13. An inventory of wetland non-passerine birds along a southeastern Brazilian coastal area

    OpenAIRE

    D.C. Tavares; S. Siciliano

    2013-01-01

    This paper presents the list of non-passerine birds of coastal environments of the Quissama municipality, northern Rio de Janeiro State, southeastern Brazil. The surveys were conducted monthly between June 2011 and May 2012. Additional ad libitum observations were made between February 2008 and July 2012. We recorded 76 waterbird species of 15 families, of which Scolopacidae was the most representative, with 15 species. The high Nearctic shorebird species richness observed in coastal lagoo...

  14. Effect of geolocators on migration and subsequent breeding performance of a long-distance passerine migrant.

    Directory of Open Access Journals (Sweden)

    Debora Arlt

    Full Text Available Geolocators are small light-weight data loggers used to track individual migratory routes, and their use has increased exponentially in birds. However, the effects of geolocators on individual performance are still poorly known. We studied geolocator effects on a long-distance migrating passerine bird, the northern wheatear (Oenanthe oenanthe L.. We asked the general question of whether geolocators affect migratory behaviour and subsequent reproductive performance of small passerines by comparing arrival time, breeding time, breeding success and survival of geolocator versus control birds of known identity and breeding history. During two years geolocator birds (n=37 displayed a lower apparent survival (30% as compared to controls (45%, n=164. Furthermore, returning geolocator birds (n=12 arrived on average 3.5 days later, started laying eggs 6.3 days later, and had lower nest success (25% than control birds (78%. Our results suggest that geolocators affect migratory performance with carry-over effects to the timing of breeding and reproductive success in the subsequent breeding season. We discuss the implications of such geolocator effects for the study of migratory strategies of small passerines in general and suggest how to identify and investigate such effects in the future.

  15. Effects of Government Grassland Conservation Policy on Household Livelihoods and Dependence on Local Grasslands: Evidence from Inner Mongolia, China

    NARCIS (Netherlands)

    Du, Bingzhen; Zhen, Lin; Yan, Huimin; Groot, de Dolf

    2016-01-01

    Grassland degradation intensifies human-environment conflicts and adversely affects local residents’ livelihoods. To reduce grassland degradation in Inner Mongolia, China, the government has enforced (since 1998) a series of grassland conservation and management policies that restrict the use of

  16. The endemic flora of Greece

    DEFF Research Database (Denmark)

    Tan, Kit

    2007-01-01

    The Balkan Peninsula has a rich endemic flora estimated as between 2600 and 2700 taxa; c. 750 are restricted to Greece. Conservationists consider the endemic flora of a country needs protection for all time; there is a tendency to paint an alarming picture. However, unless one knows something or ...... have been mapped and it is already possible to recognize the hot-spots of biodiversity as these are linked to the centres of endemism. Determining the centres of diversity is an important and significant contribution to further conservation measures at the global level....

  17. Changes in productivity of grassland with ageing

    NARCIS (Netherlands)

    Hoogerkamp, M.

    1984-01-01

    The productivity of grassland may change greatly with ageing. Frequently, a productive ley period, occurring in the first time after (re)seeding, is followed by a period in which productivity decreases. Under conditions favourable to grassland this may be temporary. A production level

  18. Effects of forest expansion on mountain grassland

    DEFF Research Database (Denmark)

    Guidi, Claudia; Magid, Jakob; Rodeghiero, Mirco

    2014-01-01

    Background and aims. Grassland abandonment followed by forest succession is the dominant land-use change in the European Alps. We studied the impact of current forest expansion on mountain grassland on changes in physical soil organic carbon (SOC) fractions along a land-use and management gradient......, focusing on changes in aggregate stability and particulate organic matter (POM). Methods. Four successional stages were investigated: managed grassland, two transitional phases in which grassland abandonment led to colonization by Picea abies (L.) Karst., and old mixed forest dominated by Fagus sylvatica L....... Results. The dimension of aggregates assessed by aggregate size fractionation tended to increase, whereas SOC allocation to stable aggregates assessed by sizedensity fractionation decreased following conversion of grassland to forest (e.g. from 81 to 59 % in the 0–5 cm layer). The amount of SOC stored...

  19. Mapping evaporative water loss in desert passerines reveals an expanding threat of lethal dehydration.

    Science.gov (United States)

    Albright, Thomas P; Mutiibwa, Denis; Gerson, Alexander R; Smith, Eric Krabbe; Talbot, William A; O'Neill, Jacqueline J; McKechnie, Andrew E; Wolf, Blair O

    2017-02-28

    Extreme high environmental temperatures produce a variety of consequences for wildlife, including mass die-offs. Heat waves are increasing in frequency, intensity, and extent, and are projected to increase further under climate change. However, the spatial and temporal dynamics of die-off risk are poorly understood. Here, we examine the effects of heat waves on evaporative water loss (EWL) and survival in five desert passerine birds across the southwestern United States using a combination of physiological data, mechanistically informed models, and hourly geospatial temperature data. We ask how rates of EWL vary with temperature across species; how frequently, over what areas, and how rapidly lethal dehydration occurs; how EWL and die-off risk vary with body mass; and how die-off risk is affected by climate warming. We find that smaller-bodied passerines are subject to higher rates of mass-specific EWL than larger-bodied counterparts and thus encounter potentially lethal conditions much more frequently, over shorter daily intervals, and over larger geographic areas. Warming by 4 °C greatly expands the extent, frequency, and intensity of dehydration risk, and introduces new threats for larger passerine birds, particularly those with limited geographic ranges. Our models reveal that increasing air temperatures and heat wave occurrence will potentially have important impacts on the water balance, daily activity, and geographic distribution of arid-zone birds. Impacts may be exacerbated by chronic effects and interactions with other environmental changes. This work underscores the importance of acute risks of high temperatures, particularly for small-bodied species, and suggests conservation of thermal refugia and water sources.

  20. Heavy metals and metalloids in egg contents and eggshells of passerine birds from Arizona

    International Nuclear Information System (INIS)

    Mora, Miguel A.

    2003-01-01

    High concentrations of Sr in eggshells may be associated with lower hatching success of some passerine birds. - Concentrations of inorganic elements were determined in eggs of passerine birds including the endangered southwestern willow flycatcher (Empidonax traillii extimus) from four regions in Arizona. The main aim of the study was to determine the distribution of metals in egg contents and eggshells, with emphasis on the deposition of Sr in eggshells. Seventy eggs of 11 passerine species were collected at four nesting locations during 2000. Aluminum, Ba, Cr, Cu, Mn, Se, Sr, and Zn, were detected primarily in egg contents of all bird species. Arsenic, Ni, Pb, and V were detected primarily in eggshells. A proportion of most inorganic elements accumulated in the eggshell. Concentrations of Ba, Cu, Mn, Se, Sr, and Zn in egg contents and As, Ba, Cu, and V in eggshells of yellow-breasted chats (Icteria virens) were similar among locations. However, concentrations of Mn, Ni, Sr, and Zn in eggshells were significant different among locations. Except for Cu, Mn, Se, and Zn, concentrations of inorganic elements were 2-35 times greater in eggshells than in eggs. Most concentrations of metals and metalloids in eggs and eggshells of all the bird species were below levels known to affect reproduction or that have other deleterious effects. However, I found somewhat elevated concentrations of Sr in eggshells (highest mean=1505 μg/g dw, n=3) of yellow-breasted chats and willow flycatchers, and in egg contents of yellow warblers (Dendroica petechia) and song sparrows (Melospiza melodia). Whether current observed concentrations of Sr in eggshells are affecting nesting birds in Arizona remains to be determined. Strontium and other metals could be associated with lower hatching success in some areas. This study shows that a proportion of many inorganic elements accumulates in the eggshell and that the potential effects on the proper structure and functioning of the eggshell

  1. Variability of annual CO2 exchange from Dutch grasslands

    NARCIS (Netherlands)

    Jacobs, C.M.J.; Jacobs, A.F.G.; Bosveld, F.C.; Hendriks, D.M.D.; Hensen, A.; Kroon, P.; Moors, E.J.; Nol, L.; Schrier-Uijl, A.P.; Veenendaal, E.M.

    2007-01-01

    An intercomparison is made of the Net Ecosystem Exchange of CO2, NEE, for eight Dutch grassland sites: four natural grasslands, two production grasslands and two meteorological stations within a rotational grassland region. At all sites the NEE was determined during at least 10 months per site,

  2. Potential impacts of climate change on the winter distribution of Afro-Palaearctic migrant passerines

    DEFF Research Database (Denmark)

    Barbet-Massin, Morgane; Walther, Bruno A; Thuiller, Wilfried

    2009-01-01

    We modelled the present and future sub-Saharan winter distributions of 64 trans-Saharan migrant passerines to predict the potential impacts of climate change. These predictions used the recent ensemble modelling developments and the latest IPCC climatic simulations to account for possible...... changes in range size and location were spatially structured, with species that winter in southern and eastern Africa facing larger range contractions and shifts. Predicted changes in regional species richness for these long-distance migrants are increases just south of the Sahara and on the Arabian...... Peninsula and major decreases in southern and eastern Africa....

  3. Satellite-based assessment of grassland yields

    Science.gov (United States)

    Grant, K.; Siegmund, R.; Wagner, M.; Hartmann, S.

    2015-04-01

    Cutting date and frequency are important parameters determining grassland yields in addition to the effects of weather, soil conditions, plant composition and fertilisation. Because accurate and area-wide data of grassland yields are currently not available, cutting frequency can be used to estimate yields. In this project, a method to detect cutting dates via surface changes in radar images is developed. The combination of this method with a grassland yield model will result in more reliable and regional-wide numbers of grassland yields. For the test-phase of the monitoring project, a study area situated southeast of Munich, Germany, was chosen due to its high density of managed grassland. For determining grassland cutting robust amplitude change detection techniques are used evaluating radar amplitude or backscatter statistics before and after the cutting event. CosmoSkyMed and Sentinel-1A data were analysed. All detected cuts were verified according to in-situ measurements recorded in a GIS database. Although the SAR systems had various acquisition geometries, the amount of detected grassland cut was quite similar. Of 154 tested grassland plots, covering in total 436 ha, 116 and 111 cuts were detected using CosmoSkyMed and Sentinel-1A radar data, respectively. Further improvement of radar data processes as well as additional analyses with higher sample number and wider land surface coverage will follow for optimisation of the method and for validation and generalisation of the results of this feasibility study. The automation of this method will than allow for an area-wide and cost efficient cutting date detection service improving grassland yield models.

  4. Not seeing the grass for the trees: Timber plantations and agriculture shrink tropical montane grassland by two-thirds over four decades in the Palani Hills, a Western Ghats Sky Island.

    Science.gov (United States)

    Arasumani, M; Khan, Danish; Das, Arundhati; Lockwood, Ian; Stewart, Robert; Kiran, Ravi A; Muthukumar, M; Bunyan, Milind; Robin, V V

    2018-01-01

    Tropical montane habitats, grasslands, in particular, merit urgent conservation attention owing to the disproportionate levels of endemic biodiversity they harbour, the ecosystem services they provide, and the fact that they are among the most threatened habitats globally. The Shola Sky Islands in the Western Ghats host a matrix of native forest-grassland matrix that has been planted over the last century, with exotic timber plantations. The popular discourse on the landscape change is that mainly forests have been lost to the timber plantations and recent court directives are to restore Shola forest trees. In this study, we examine spatiotemporal patterns of landscape change over the last 40 years in the Palani Hills, a significant part of the montane habitat in the Western Ghats. Using satellite imagery and field surveys, we find that 66% of native grasslands and 31% of native forests have been lost over the last 40 years. Grasslands have gone from being the dominant, most contiguous land cover to one of the rarest and most fragmented. They have been replaced by timber plantations and, to a lesser extent, expanding agriculture. We find that the spatial pattern of grassland loss to plantations differs from the loss to agriculture, likely driven by the invasion of plantation species into grasslands. We identify remnant grasslands that should be prioritised for conservation and make specific recommendations for conservation and restoration of grasslands in light of current management policy in the Palani Hills, which favours large-scale removal of plantations and emphasises the restoration of native forests.

  5. Breeding biology of passerines in a subtropical montane forest in northwestern Argentina

    Science.gov (United States)

    Auer, S.K.; Bassar, R.D.; Fontaine, J.J.; Martin, T.E.

    2007-01-01

    The breeding ecology of south temperate bird species is less widely known than that of north temperate species, yet because they comprise a large portion of the world's avian diversity, knowledge of their breeding ecology can contribute to a more comprehensive understanding of the geographic diversity of avian reproductive traits and life history strategies. We provide the first detailed examination of the reproductive strategies of 18 forest passerines of subtropical, northwestern Argentina. Mean clutch sizes were smaller and egg mass was greater than for north temperate birds, but differed among species and nest types, with cavity-nesters having larger clutches than species with open-cup and enclosed nests. Across all species, the average breeding season duration was 50 days; thus, the common perception that southern species have smaller clutch sizes because of longer breeding seasons is not supported in this community. Daily nest predation rates were influenced by nest type, cavity nests suffering the least from predation, as found in north temperate systems. Only females incubated eggs in all but one species, whereas both parents fed and cared for nestlings in all species. Mean nest attentiveness was low compared to north temperate passerines. Mean hourly nestling feeding rates differed among species and were negatively related to nest predation risk. In short, coexisting species in this subtropical forest varied in their life history strategies, in part correlated with variation in nest predation risk, but also differing from north temperate species. ?? The Cooper Ornithological Society 2007.

  6. Feather mites (Acari, Astigmata from Azorean passerines (Aves, Passeriformes: lower species richness compared to European mainland

    Directory of Open Access Journals (Sweden)

    Rodrigues Pedro

    2015-01-01

    Full Text Available Ten passerine species were examined on three islands of the Azores (North Atlantic during 2013 and 2014 in order to identify their feather mite assemblages. We recorded 19 feather mite species belonging to four families of the superfamily Analgoidea (Analgidae, Proctophyllodidae, Psoroptoididae and Trouessartiidae. A high prevalence of feather mite species was recorded on the majority of the examined host species. Only three passerine species (Sylvia atricapilla, Regulus regulus and Serinus canaria presented the same full complex of mite species as commonly occurs in the plumage of their closest relatives in continental Europe. Passer domesticus presented the same limited fauna of feather mites living in the plumage as do its co-specifics in continental Europe. Carduelis carduelis bears the same feather mite species as do most of its continental populations in Europe, but it lacks one mite species occurring on this host in Egypt. Turdus merula, Pyrrhula murina and Fringilla coelebs are missing several mite species common to their continental relatives. This diminution could be explained by the founder effect, whereby a limited number of colonizing individuals did not transport the full set of feather mite species, or by the extinction of some mite species after initially having reached the Azores. The only individual of Motacilla cinerea sampled in this study presented a new host record for the mite species Trouessartia jedliczkai.

  7. Species- and age-related variation in metal exposure and accumulation of two passerine bird species

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, A.M.M., E-mail: asa.berglund@emg.umu.se [Section of Ecology, 20014 University of Turku (Finland); Koivula, M.J.; Eeva, T. [Section of Ecology, 20014 University of Turku (Finland)

    2011-10-15

    We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: > We measured metal concentrations in feces and livers of two passerine species. > We examined species- and age-related differences in polluted environments. > Feces was evaluated as a useful non-destructive measure of increased stress. > Generally pied flycatchers accumulated higher concentrations than great tits. > Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

  8. Species- and age-related variation in metal exposure and accumulation of two passerine bird species

    International Nuclear Information System (INIS)

    Berglund, A.M.M.; Koivula, M.J.; Eeva, T.

    2011-01-01

    We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: → We measured metal concentrations in feces and livers of two passerine species. → We examined species- and age-related differences in polluted environments. → Feces was evaluated as a useful non-destructive measure of increased stress. → Generally pied flycatchers accumulated higher concentrations than great tits. → Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

  9. Codiversification of gastrointestinal microbiota and phylogeny in passerines is not explained by ecological divergence.

    Science.gov (United States)

    Kropáčková, Lucie; Těšický, Martin; Albrecht, Tomáš; Kubovčiak, Jan; Čížková, Dagmar; Tomášek, Oldřich; Martin, Jean-François; Bobek, Lukáš; Králová, Tereza; Procházka, Petr; Kreisinger, Jakub

    2017-10-01

    Vertebrate gut microbiota (GM) is comprised of a taxonomically diverse consortium of symbiotic and commensal microorganisms that have a pronounced effect on host physiology, immune system function and health status. Despite much research on interactions between hosts and their GM, the factors affecting inter- and intraspecific GM variation in wild populations are still poorly known. We analysed data on faecal microbiota composition in 51 passerine species (319 individuals) using Illumina MiSeq sequencing of bacterial 16S rRNA (V3-V4 variable region). Despite pronounced interindividual variation, GM composition exhibited significant differences at the interspecific level, accounting for approximately 20%-30% of total GM variation. We also observed a significant correlation between GM composition divergence and host's phylogenetic divergence, with strength of correlation higher than that of GM vs. ecological or life history traits and geographic variation. The effect of host's phylogeny on GM composition was significant, even after statistical control for these confounding factors. Hence, our data do not support codiversification of GM and passerine phylogeny solely as a by-product of their ecological divergence. Furthermore, our findings do not support that GM vs. host's phylogeny codiversification is driven primarily through trans-generational GM transfer as the GM vs. phylogeny correlation does not increase with higher sequence similarity used when delimiting operational taxonomic units. Instead, we hypothesize that the GM vs. phylogeny correlation may arise as a consequence of interspecific divergence of genes that directly or indirectly modulate composition of GM. © 2017 John Wiley & Sons Ltd.

  10. How unpredictable access to food increases the body fat of small passerines: A mechanistic approach.

    Science.gov (United States)

    Anselme, Patrick; Otto, Tobias; Güntürkün, Onur

    2017-11-01

    Unpredictable rewards increase the vigor of responses in autoshaping (a Pavlovian conditioning procedure) and are preferred to predictable rewards in free-choice tasks involving fixed- versus variable-delay schedules. The significance those behavioral properties may have in field conditions is currently unknown. However, it is noticeable that when exposed to unpredictable food, small passerines - such as robins, titmice, and starlings - get fatter than when food is abundant. In functional terms, fattening is viewed as an evolutionary strategy acting against the risk of starvation when food is in short supply. But this functional view does not explain the causal mechanisms by which small passerines come to be fatter under food uncertainty. Here, it is suggested that one of these causal mechanisms is that involved in behavioral invigoration and preference for food uncertainty in the laboratory. Based on a psychological theory of motivational changes under food uncertainty, we developed an integrative computational model to test this idea. We show that, for functional (adaptive) reasons, the excitatory property of reward unpredictability can underlie the propensity of wild birds to forage longer and/or more intensively in an unpredictable environment, with the consequence that they can put on more fat reserves. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Description of the Grassland Biome Project

    CSIR Research Space (South Africa)

    Mentis, MT

    1982-10-01

    Full Text Available The objectives, organization and research programme of the Grassland Biome Project are described against a background of the biome's ecological characteristics and environmental problems. Four principal research topics wil 1 be focused upon: (i...

  12. Soil disturbance as a grassland restoration measure

    DEFF Research Database (Denmark)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success...... to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration...

  13. Notes on the flowering and pollination of the endemic grassland Aloe reitzii var. reitzii (Asphodelaceae

    Directory of Open Access Journals (Sweden)

    Craig T. Symes

    2017-08-01

    Conclusion: Because birds are important pollinators for many Aloe species, it is assumed that the bird species detected visiting A. reitzii var. reitzii are similarly important pollinators. At least 10 invertebrate species and sengi (Elephantulus sp. were also recorded as visitors to flowers, but they may be less important pollinators than specialist and generalist avian nectarivores. This study provides further insight into the pollination biology of a diverse, and ecologically important, succulent genus in Africa.

  14. Effects of grassland management on the emission of methane from grassland on peat soils

    Energy Technology Data Exchange (ETDEWEB)

    Van Dasselaar, A. [Dept. of Soil Science and Plant Nutrition, Wageningen Agricultural Univ. (Netherlands); Oenema, O. [NMI, Wageningen (Netherlands)

    1995-11-01

    Net methane (CH{sub 4}) emissions from managed grassland on peat soils in the Netherlands have been monitored with vented closed flux chambers in the period January - June 1994. Net CH{sub 4} emissions from two intensively managed grasslands were low, in general less than 0.1 mg CH{sub 4} m{sup -2} d{sup -l}. On these sites, the effect of management was negligibly small. CH{sub 4} emission from three extensively managed grasslands in a nature preserve ranged from 0 to 185 mg CH{sub 4} m{sup -2} d{sup -l}. The results presented here indicate that CH{sub 4} emissions are 2-3 orders of magnitude higher on extensively managed grasslands than on intensively managed grasslands. 2 figs., 6 refs.

  15. Plutonium in a grassland ecosystem

    International Nuclear Information System (INIS)

    Little, C.A.

    1976-08-01

    A study was made of plutonium contamination of grassland at the Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geographical areas; whether or not the predominant isotopes, 238 Pu and 239 Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for Pu analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99 percent of the total plutonium was contained in the soil and the concentrations were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes

  16. A comprehensive analysis of small-passerine fatalities from collision with turbines at wind energy facilities.

    Directory of Open Access Journals (Sweden)

    Wallace P Erickson

    Full Text Available Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 116 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to calculate estimates of small-bird fatality rates from reported all-bird rates for 30% of studies. The remaining 70% of studies provided data on small-bird fatalities. We then adjusted estimates to account for detection bias and loss of carcasses from scavenging. These studies represented about 15% of current operating capacity (megawatts [MW] for all wind energy facilities in the US and Canada and provided information on 4,975 bird fatalities, of which we estimated 62.5% were small passerines comprising 156 species. For all wind energy facilities currently in operation, we estimated that about 134,000 to 230,000 small-passerine fatalities from collision with wind turbines occur annually, or 2.10 to 3.35 small birds/MW of installed capacity. When adjusted for species composition, this indicates that about 368,000 fatalities for all bird species are caused annually by collisions with wind turbines. Other human-related sources of bird deaths, (e.g., communication towers, buildings [including windows], and domestic cats have been estimated to kill millions to billions of birds each year. Compared to continent-wide population estimates, the cumulative mortality rate per year by species was highest for black-throated blue warbler and tree swallow; 0.043% of the entire population of each species was estimated to annually suffer mortality from collisions with turbines. For the eighteen species with the next highest values, this estimate ranged from 0.008% to 0.038%, much lower than rates attributed to collisions with communication towers (1.2% to 9.0% for top

  17. A comprehensive analysis of small-passerine fatalities from collision with turbines at wind energy facilities.

    Science.gov (United States)

    Erickson, Wallace P; Wolfe, Melissa M; Bay, Kimberly J; Johnson, Douglas H; Gehring, Joelle L

    2014-01-01

    Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 116 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to calculate estimates of small-bird fatality rates from reported all-bird rates for 30% of studies. The remaining 70% of studies provided data on small-bird fatalities. We then adjusted estimates to account for detection bias and loss of carcasses from scavenging. These studies represented about 15% of current operating capacity (megawatts [MW]) for all wind energy facilities in the US and Canada and provided information on 4,975 bird fatalities, of which we estimated 62.5% were small passerines comprising 156 species. For all wind energy facilities currently in operation, we estimated that about 134,000 to 230,000 small-passerine fatalities from collision with wind turbines occur annually, or 2.10 to 3.35 small birds/MW of installed capacity. When adjusted for species composition, this indicates that about 368,000 fatalities for all bird species are caused annually by collisions with wind turbines. Other human-related sources of bird deaths, (e.g., communication towers, buildings [including windows]), and domestic cats) have been estimated to kill millions to billions of birds each year. Compared to continent-wide population estimates, the cumulative mortality rate per year by species was highest for black-throated blue warbler and tree swallow; 0.043% of the entire population of each species was estimated to annually suffer mortality from collisions with turbines. For the eighteen species with the next highest values, this estimate ranged from 0.008% to 0.038%, much lower than rates attributed to collisions with communication towers (1.2% to 9.0% for top twenty species).

  18. A comprehensive analysis of small-passerine fatalities from collisions with turbines at wind energy facilities

    Science.gov (United States)

    Erickson, Wallace P.; Wolfe, Melissa M.; Bay, Kimberly J.; Johnson, Douglas H.; Gehring, Joelle L.

    2014-01-01

    Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 39 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to calculate estimates of small-bird fatality rates from reported all-bird rates for 30% of studies. The remaining 70% of studies provided data on small-bird fatalities. We then adjusted estimates to account for detection bias and loss of carcasses from scavenging. These studies represented about 15% of current operating capacity (megawatts [MW]) for all wind energy facilities in the US and Canada and provided information on 4,975 bird fatalities, of which we estimated 62.5% were small passerines comprising 156 species. For all wind energy facilities currently in operation, we estimated that about 134,000 to 230,000 small-passerine fatalities from collision with wind turbines occur annually, or 2.10 to 3.35 small birds/MW of installed capacity. When adjusted for species composition, this indicates that about 368,000 fatalities for all bird species are caused annually by collisions with wind turbines. Other human-related sources of bird deaths, (e.g., communication towers, buildings [including windows]), and domestic cats) have been estimated to kill millions to billions of birds each year. Compared to continent-wide population estimates, the cumulative mortality rate per year by species was highest for black-throated blue warbler and tree swallow; 0.043% of the entire population of each species was estimated to annually suffer mortality from collisions with turbines. For the eighteen species with the next highest values, this estimate ranged from 0.008% to 0.038%, much lower than rates attributed to collisions with communication towers (1.2% to 9.0% for top twenty species).

  19. Mammal endemism In Italy: A review

    Directory of Open Access Journals (Sweden)

    Giovanni Amori

    2018-02-01

    Full Text Available Although there are various checklists of Italian mammals, there is not yet a synthesis of those mammals that are endemic to Italy. Therefore, we provide for the first time a detailed review on Italian mammal endemic species including endemic taxa deserving additional studies. This review is based on the most recent taxonomic revisions obtained using Scopus and Google Scholar databases. We also considered the age of endemic species. Some aspects of mammalian conservation are also provided and discussed.

  20. Preliminary Research on Grassland Fine-classification Based on MODIS

    International Nuclear Information System (INIS)

    Hu, Z W; Zhang, S; Yu, X Y; Wang, X S

    2014-01-01

    Grassland ecosystem is important for climatic regulation, maintaining the soil and water. Research on the grassland monitoring method could provide effective reference for grassland resource investigation. In this study, we used the vegetation index method for grassland classification. There are several types of climate in China. Therefore, we need to use China's Main Climate Zone Maps and divide the study region into four climate zones. Based on grassland classification system of the first nation-wide grass resource survey in China, we established a new grassland classification system which is only suitable for this research. We used MODIS images as the basic data resources, and use the expert classifier method to perform grassland classification. Based on the 1:1,000,000 Grassland Resource Map of China, we obtained the basic distribution of all the grassland types and selected 20 samples evenly distributed in each type, then used NDVI/EVI product to summarize different spectral features of different grassland types. Finally, we introduced other classification auxiliary data, such as elevation, accumulate temperature (AT), humidity index (HI) and rainfall. China's nation-wide grassland classification map is resulted by merging the grassland in different climate zone. The overall classification accuracy is 60.4%. The result indicated that expert classifier is proper for national wide grassland classification, but the classification accuracy need to be improved

  1. Some Insights on Grassland Health Assessment Based on Remote Sensing

    Directory of Open Access Journals (Sweden)

    Dandan Xu

    2015-01-01

    Full Text Available Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.

  2. Some insights on grassland health assessment based on remote sensing.

    Science.gov (United States)

    Xu, Dandan; Guo, Xulin

    2015-01-29

    Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.

  3. Endemic Images and the Desensitization Process.

    Science.gov (United States)

    Saigh, Philip A.; Antoun, Fouad T.

    1984-01-01

    Examined the effects of endemic images on levels of anxiety and achievement of 48 high school students. Results suggested that a combination of endemic images and study skills training was as effective as desensitization plus study skills training. Includes the endemic image questionnaire. (JAC)

  4. Importance and functions of European grasslands.

    Science.gov (United States)

    Carlier, L; De Vliegher, A; Van Cleemput, O; Boeckx, P

    2005-01-01

    The European agricultural policy is not simple and needs to accommodate also social and environmental requirements. Grassland will continue to be an important form of land use in Europe, but with increased diversity in management objectives and systems used. Besides its role as basic nutrient for herbivores and ruminants grasslands have opportunities for adding value by exploiting positive health characteristics in animal products from grassland and through the delivery of environmental benefits. In fact grasslands contribute to a high degree to the struggle against erosion and to the regularizing of water regimes, to the purification of fertilizers and pesticides and to biodiversity. Finally they have aesthetic role and recreational function as far as they provide public access that other agricultural uses do not allow. But even for grassland it is very difficult to create a good frame for its different tasks (1) the provision of forage for livestock, (2) protection and conservation of soil and water resources, (3) furnishing a habitat for wildlife, both flora and fauna and (4) contribution to the attractiveness of the landscape. Nevertheless it is the only crop, able to fulfil so many tasks and to fit so many requirements.

  5. [Research progress and trend on grassland agroecology].

    Science.gov (United States)

    Ren, Jizhou; Li, Xianglin; Hou, Fujiang

    2002-08-01

    The connotation, progress, research frontiers and developmental trend of grassland agroecology are discussed in this paper. The interface theory, structure and function, coupling and discordance, and health assessment of grassland agroecosystems were recognized as the four research frontiers of the discipline. There exist three primary interfaces in a grassland agroecosystem, i.e., vegetation-site, grassland-animal and production-management. Research into a series of the ecological processes that occurred at these interfaces is the key to revealing the features of the system behavior. There are four sections in a grassland agroecosystem, i.e., pre-plant, plant, animal and post-biotic sections. System coupling and discordance are the two important concepts to describe interactions among the production sections. System coupling among the sections can lead to system improvement by exerting the potential of system capacity. Health of an ecosystem is a reflection of its structure and function, and health assessment is a measurement of its orderliness and service value.

  6. Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain)

    Science.gov (United States)

    Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

    2016-01-01

    Abstract In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:26865820

  7. Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain).

    Science.gov (United States)

    Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

    2016-01-01

    In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area.

  8. The intensity threshold of colour vision in a passerine bird, the blue tit (Cyanistes caeruleus).

    Science.gov (United States)

    Gomez, Doris; Grégoire, Arnaud; Del Rey Granado, Maria; Bassoul, Marine; Degueldre, David; Perret, Philippe; Doutrelant, Claire

    2014-11-01

    Many vertebrates use colour vision for vital behaviour but their visual performance in dim light is largely unknown. The light intensity threshold of colour vision is known only for humans, horses and two parrot species. Here, we first explore this threshold in a passerine bird, the blue tit (Cyanistes caeruleus). Using classic conditioning of colour cues to food rewards in three individuals, we find a threshold ranging from 0.05 to 0.2 cd m(-2). Results are comparable to the two previously tested bird species. For tits, nest light conditions probably exceed that threshold, at least after sunrise. These results shed new light on the lively debate questioning the visual performance of cavity nesters and the evolutionary significance of egg and chick coloration. Although this needs further investigation, it is possible that blue tits exploit both colour and brightness cues when viewing their eggs, chicks or conspecifics in their nests. © 2014. Published by The Company of Biologists Ltd.

  9. Habitat constraints on the distribution of passerine residents and neotropical migrants in Latin America

    Science.gov (United States)

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.

    1994-01-01

    With continuing tropical deforestation, there is increased concern for birds that depend on forest habitats in Latin America. During the past 10 northern winters, we have conducted quantitative studies of habitat use by wintering migrant songbirds and by residents in the Greater Antilles, Mexico, Central America, and northern South America. Many migrants, but few residents, winter in forest fragments and in certain arboreal agricultural habitats (citrus, cacao, shade coffee). Many other agricultural habitats (sun coffee, mango, commercial banana plantations, and heavily grazed pasture) are avoided by most birds. Some species, such as thrushes and ground-feeding warblers, depend on closed-canopy forest. Some, such as Northern Waterthrush (Seiurus noveboracensis) and Prothonotary Warbler (Protonotaria citrea), winter primarily in mangroves or other swamp forests. The majority of neotropical migrant passerines winter in forest fragments and certain agricultural habitats, as well as mature forest; but many resident species, especially suboscines (Furnariidae, Dendrocolaptidae, Formicariidae, Papridae), are heavily impacted by loss and fragmentation of the forest.

  10. The use of passerine feathers to evaluate heavy metal pollution in Central Portugal.

    Science.gov (United States)

    Costa, R A; Petronilho, J M S; Soares, A M V M; Vingada, J V

    2011-03-01

    In 2003, two sampling strategies were applied in order to evaluate metal contamination in passerine bird feathers. One strategy included the use of nest boxes and nestling great tits in a forest habitat (MU). The other strategy focused on the use of mist nets to capture adult blackbirds, robins and blackcaps in a fragmented non-forested habitat (EST). There was a significantly higher concentration of mercury in great tits (1.09 ± 0.40) sampled in MU and also in robins (3.44 ± 0.91) and blackcaps (1.62 ± 1.99) sampled in EST, in comparison to the reference site (0.66 ± 0.68; 2.04 ± 1.12; 0.32 ± 0.43; respectively). Concerning interspecific differences, robins accumulated significantly more metals than blackbirds or blackcaps.

  11. Nesting and acoustic ecology, but not phylogeny, influence passerine urban tolerance.

    Science.gov (United States)

    Cardoso, Gonçalo C

    2014-03-01

    Urbanization is one of the most extensive and ecologically significant changes happening to terrestrial environments, as it strongly affects the distribution of biodiversity. It is well established that native species richness is reduced in urban and suburban areas, but the species traits that predict tolerance to urbanization are yet little understood. In birds, one of the most studied groups in this respect, evidence is appearing that acoustic traits influence urban living, but it remains unknown how this compares to the effects of more obvious ecological traits that facilitate urban living. Therefore, it remains unclear whether acoustic communication is an important predictor of urban tolerance among species. Here, with a comparative study across 140 European and North American passerines, I show that high song frequency, which is less masked by the low-frequency anthropogenic noise, is associated with urban tolerance, with an effect size over half that of the most important ecological trait studied: off-ground nesting. Other nesting and foraging traits accepted to facilitate urban living did not differ for species occurring in urban environments. Thus, the contribution of acoustic traits for passerine urban tolerance approximates that of more obvious ecological traits. Nonetheless, effect sizes of the biological predictors of urban tolerance were low and the phylogenetic signal for urban tolerance was null, both of which suggest that factors other than phenotypic traits have major effects on urban tolerance. A simple possibility is exposure to urbanization, as there was a higher proportion of urban-tolerant species in Europe, which is more urbanized than North America. © 2013 John Wiley & Sons Ltd.

  12. Snowpack and variation in reproductive ecology of a montane ground-nesting passerine, Junco hyemalis

    Science.gov (United States)

    Smith, Kimberly G.; Andersen, Douglas C.

    1985-01-01

    Effects of snow depth and rate of snowmelt on reproduction of a montane ground-nesting passerine were examined in a 5-year study of Dark-eyed Juncos Junco hyemalis in northern Utah, USA. Distribution of clucth sizes differed significantly among years. Although most clutches contained four eggs, 3-egg clutches, due primarily to second nestings, were more common during a year of early snowmelt and 5-egg clutches were most common during two years of late snowmelt. Average clutch size was lowest in an early snowmelt year and average clutch size and date at which meadows became snow-free were significantly positively correlated. Average hatching date of 4-egg clutches was also significantly positively correlated with date at which meadows became snow-free demonstrating that most birds tracked the pattern of snowmelt. Early snowmelt may allow more pairs to attempt second nesting, but late-lying snow causes breeding to be delayed, allowing time for only one nesting attempt. During this delay, female juncos continue to feed and some may gain enough reserves to produce larger clutches, accounting for the increase in average clutch size in years of late snowmelt. Three female juncos examined in June 1982, a period of late snowmelt, had significantly more lipid reserves than did six males collected at the same time, suggesting that females are not physiologically stressed while awaiting snowmelt. By tracking snowmelt patterns, juncos synchronize production of young with peak summer insect abundance and potentially decrease risk of predation. Snow depth and rate of snowmelt are thus proximate environmental factors that may influence the reproductive ecology of ground-nesting passerines.

  13. Selection of passerine birds as bio-sentinel of persistent organic pollutants in terrestrial environment.

    Science.gov (United States)

    Mo, Ling; Zheng, Xiaobo; Sun, Yuxin; Yu, Lehuan; Luo, Xiaojun; Xu, Xiangrong; Qin, Xiaoquan; Gao, Yongli; Mai, Bixian

    2018-08-15

    A broad suite of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dichlorodiphenyltrichloroethane (DDT) and its metabolites, were analyzed in pectoral muscle of eight terrestrial passerine bird species from an extensive e-waste recycling site in South China. Concentrations of PCBs, PBDEs, and DDTs in bird samples ranged from 1260-279,000, 121-14,200, and 31-7910ng/g lipid weight, respectively. Insectivorous birds had significantly higher levels of PCBs, PBDEs, and DDTs than those in granivorous birds. Concentrations of POPs in resident insectivorous birds were significantly greater than those in migrant insectivorous birds. PCBs were the predominant pollutants in all bird species from the e-waste site, followed by PBDEs and DDTs, indicating that PCBs were mainly derived from e-wastes. The granivorous birds had higher proportions of hepta-CBs in total PCBs and higher proportions of octa- to deca-BDEs in total PBDEs compared with the insectivorous birds. The various dietary sources, migration behavior, and possible biotransformation were suspected as reasons of the distinct profiles of POPs in different bird species. The δ 15 N values were significantly and positively correlated with concentrations of POPs in resident insectivorous birds, but not in other passerine bird species, suggesting the influence of trophic levels on bioaccumulation of POPs in resident insectivorous birds. The resident insectivorous birds seem to be promising bio-sentinel of POPs in terrestrial environment around the e-waste sites. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

    Science.gov (United States)

    Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

    Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

  15. Heavy metals and metalloids in egg contents and eggshells of passerine birds from Arizona

    Science.gov (United States)

    Mora, Miguel A.

    2003-01-01

    Concentrations of inorganic elements were determined in eggs of passerine birds including the endangered southwestern willow flycatcher (Empidonax traillii extimus) from four regions in Arizona. The main aim of the study was to determine the distribution of metals in egg contents and eggshells, with emphasis on the deposition of Sr in eggshells. Seventy eggs of 11 passerine species were collected at four nesting locations during 2000. Aluminum, Ba, Cr, Cu, Mn, Se, Sr, and Zn, were detected primarily in egg contents of all bird species. Arsenic, Ni, Pb, and V were detected primarily in eggshells. A proportion of most inorganic elements accumulated in the eggshell. Concentrations of Ba, Cu, Mn, Se, Sr, and Zn in egg contents and As, Ba, Cu, and V in eggshells of yellow-breasted chats (Icteria virens) were similar among locations. However, concentrations of Mn, Ni, Sr, and Zn in eggshells were significant different among locations. Except for Cu, Mn, Se, and Zn, concentrations of inorganic elements were 2–35 times greater in eggshells than in eggs. Most concentrations of metals and metalloids in eggs and eggshells of all the bird species were below levels known to affect reproduction or that have other deleterious effects. However, I found somewhat elevated concentrations of Sr in eggshells (highest mean=1505 μg/g dw, n=3) of yellow-breasted chats and willow flycatchers, and in egg contents of yellow warblers (Dendroica petechia) and song sparrows (Melospiza melodia). Whether current observed concentrations of Sr in eggshells are affecting nesting birds in Arizona remains to be determined. Strontium and other metals could be associated with lower hatching success in some areas. This study shows that a proportion of many inorganic elements accumulates in the eggshell and that the potential effects on the proper structure and functioning of the eggshell should not be ignored.

  16. Plutonium in a grassland ecosystem

    International Nuclear Information System (INIS)

    Little, C.A.

    1976-01-01

    This study was concerned with plutonium contamination of grassland at the U.S. Energy Research and Development Administration Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geogrphical areas; whether or not the predominant isotopes, 238 Pu and 239 Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for plutonium analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99% of the total plutonium was contained in the soil. The concentrations of plutonium in soil were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes. A mechanism of agglomerated submicron plutonium oxide particles and larger (1-500 μm) host soil particles was proposed. Concentrations of Pu in litter and vegetation were inversely correlated to distance from the source and directly correlated to soil concentrations at the same location. Comparatively high concentration ratios of vegetation to soil suggested wind resuspension of contamination as an important transport mechanism. Arthropod and small mammal samples were highly skewed, kurtotic, and quite variable, having coefficients of variation (standard deviation/mean) as high as 600%. Bone Pu concentrations were lower than other tissues. Hide, GI, and lung were generally not higher in Pu than kidney, liver and muscle

  17. The community ecology of barley/cereal yellow dwarf viruses in Western US grasslands.

    Science.gov (United States)

    Power, Alison G; Borer, Elizabeth T; Hosseini, Parviez; Mitchell, Charles E; Seabloom, Eric W

    2011-08-01

    Research on plant viruses in natural ecosystems has been increasing rapidly over the past decade. This paper reviews recent research on the barley and cereal yellow dwarf viruses (B/CYDVs) in grasslands of the western US, beginning with the evidence that the disease caused by these viruses facilitated the invasion of western US grasslands by European annual grasses. Observational and experimental studies of B/CYDVs were carried out along a latitudinal gradient (33.8-48.8°N) from southern California to southern Canada. The prevalence and community composition of B/CYDVs were assessed over a variety of scales and under a range of biotic and abiotic conditions. The findings indicate that both biotic and abiotic factors are important influences on virus ecology and epidemiology. Introduced annual grasses are high-quality hosts that amplify both virus and vector populations in this system, but our research suggests that endemic perennial grasses are critically important for sustaining virus populations in contemporary grasslands largely composed of introduced species. Experiments indicated that increased phosphorus supply to hosts resulted in greater host biomass and higher virus prevalence. Using experimental exclosures, it was found that the presence of grazing vertebrate herbivores increased the abundance of annual grasses, resulting in increased virus prevalence. The results of these studies suggest that patterns of B/CYDV prevalence and coinfection in western US grasslands are strongly shaped by the interactions of host plants, vectors, vertebrate herbivores, and abiotic drivers including nutrients. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Endemic Nephropathy Around the World.

    Science.gov (United States)

    Gifford, Fiona J; Gifford, Robert M; Eddleston, Michael; Dhaun, Neeraj

    2017-03-01

    There have been several global epidemics of chronic kidney disease of unknown etiology (CKD u ). Some, such as Itai-Itai disease in Japan and Balkan endemic nephropathy, have been explained, whereas the etiology of others remains unclear. In countries such as Sri Lanka, El Salvador, Nicaragua, and India, CKD u is a major public health problem and causes significant morbidity and mortality. Despite their geographical separation, however, there are striking similarities between these endemic nephropathies. Young male agricultural workers who perform strenuous labor in extreme conditions are the worst affected. Patients remain asymptomatic until end-stage renal failure. Biomarkers of tubular injury are raised, and kidney biopsy shows chronic interstitial nephritis with associated tubular atrophy. In many of these places access to dialysis and transplantation is limited, leaving few treatment options. In this review we briefly describe the major historic endemic nephropathies. We then summarize the epidemiology, clinical features, histology and clinical course of CKD u in Mesoamerica, Sri Lanka, India, Egypt, and Tunisia. We draw comparisons between the proposed etiologies and supporting research. Recognition of the similarities may reinforce the international drive to establish causality and to effect prevention.

  19. Endemic Nephropathy Around the World

    Directory of Open Access Journals (Sweden)

    Fiona J. Gifford

    2017-03-01

    Full Text Available There have been several global epidemics of chronic kidney disease of unknown etiology (CKDu. Some, such as Itai-Itai disease in Japan and Balkan endemic nephropathy, have been explained, whereas the etiology of others remains unclear. In countries such as Sri Lanka, El Salvador, Nicaragua, and India, CKDu is a major public health problem and causes significant morbidity and mortality. Despite their geographical separation, however, there are striking similarities between these endemic nephropathies. Young male agricultural workers who perform strenuous labor in extreme conditions are the worst affected. Patients remain asymptomatic until end-stage renal failure. Biomarkers of tubular injury are raised, and kidney biopsy shows chronic interstitial nephritis with associated tubular atrophy. In many of these places access to dialysis and transplantation is limited, leaving few treatment options. In this review we briefly describe the major historic endemic nephropathies. We then summarize the epidemiology, clinical features, histology and clinical course of CKDu in Mesoamerica, Sri Lanka, India, Egypt, and Tunisia. We draw comparisons between the proposed etiologies and supporting research. Recognition of the similarities may reinforce the international drive to establish causality and to effect prevention.

  20. Distinguishing Intensity Levels of Grassland Fertilization Using Vegetation Indices

    OpenAIRE

    Jens L. Hollberg; Jürgen Schellberg

    2017-01-01

    Monitoring the reaction of grassland canopies on fertilizer application is of major importance to enable a well-adjusted management supporting a sustainable production of the grass crop. Up to date, grassland managers estimate the nutrient status and growth dynamics of grasslands by costly and time-consuming field surveys, which only provide low temporal and spatial data density. Grassland mapping using remotely-sensed Vegetation Indices (VIs) has the potential to contribute to solving these ...

  1. Bird communities and biomass yields in potential bioenergy grasslands.

    Directory of Open Access Journals (Sweden)

    Peter J Blank

    Full Text Available Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields, and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes.

  2. Small mammals as indicators of cryptic plant species diversity in the central Chilean plant endemicity hotspot

    Directory of Open Access Journals (Sweden)

    Meredith Root-Bernstein

    2014-12-01

    Full Text Available Indicator species could help to compensate for a shortfall of knowledge about the diversity and distributions of undersampled and cryptic species. This paper provides background knowledge about the ecological interactions that affect and are affected by herbaceous diversity in central Chile, as part of the indicator species selection process. We focus on the ecosystem engineering role of small mammals, primarily the degu Octodon degus. We also consider the interacting effects of shrubs, trees, avian activity, livestock, slope, and soil quality on herbaceous communities in central Chile. We sampled herbaceous diversity on a private landholding characterized by a mosaic of savanna, grassland and matorral, across a range of degu disturbance intensities. We find that the strongest factors affecting endemic herbaceous diversity are density of degu runways, shrub cover and avian activity. Our results show that the degu, a charismatic and easily identifiable and countable species, could be used as an indicator species to aid potential conservation actions such as private protected area uptake. We map areas in central Chile where degus may indicate endemic plant diversity. This area is larger than expected, and suggests that significant areas of endemic plant communities may still exist, and should be identified and protected. Keywords: Cryptic species, Diversity, Endemic, Indicator species, Octodon degus, Plant

  3. Soil acidification and liming in grassland production and grassland soil fertility in Slovenia

    Directory of Open Access Journals (Sweden)

    Jure ČOP

    2015-12-01

    Full Text Available This paper reviews the evidences on grassland soil acidity and liming in relation to soil processes and herbage production. There is also an outline of the present state of soil acidity and acidity-related traits – contents of organic matter (OM, phosphorus (P and potassium (K in Slovene grassland. In grassland, soil acidification is an ongoing process under humid climate conditions. It is mainly driven by leaching of nutrients, net loss of cations due to retention in livestock products, use of physiologically acid fertilizers, acid rain and N2 fixation. This process is reduced by strong pH buffering capacity of the soil and by physiologically basic fertilizers. Acid grassland soils in Slovenia are widely distributed in spite of the fact that 44% of the total land has developed from a carbonate parent material. Of the 1713 grassland soil samples analysed during 2005-2007 45% were regarded as acid ones (pH < 5.5; in KCl, 57% as soils with very low P status (˂ 6 mg P2O5/100 g soil and 22% as soils with very low K status (˂ 10 mg K2O/100 soil. Increased content of soil organic matter was identified for alpine pastures (˃ 10 % OM in 44% of samples, mainly as a result of low decomposition rate. Liming of acid grassland soils did not always reflect in a higher herbage yield. The cause for this inefficiency is plant composition of grassland. Thus, many grassland plants with relatively high production potential have adapted to acid soil conditions. To illustrate the inconsistent liming effect three researches are reviewed. In the first two researches liming along with fertilizer application did not increase the yield comparing to the fertilized control while in the third research the increase amounted 26 %. Liming improves considerably botanical composition of the acid grassland (e.g. sward where Common Bent – Agrostis tenuis Sibth. – prevails and thus indirectly affects palatability and nutritive value of herbage. Grassland liming has a weak

  4. Grassland ecology and diversity (Ecologia y diversidad de pastizales)

    Science.gov (United States)

    Laurie B. Abbott

    2006-01-01

    Grasslands of the Chihuahuan Desert region are ecologically and economically important. These grasslands are valued for their rangeland, wildlife, watershed, and recreation resources. Biological diversity also raises the value of grassland communities. The potential for multiple uses within the region increases as the diversity of the resource base increases. In order...

  5. Appreciation of the functions of grasslands by Irish stakeholders

    NARCIS (Netherlands)

    Hennessy, D.; Pol-van Dasselaar, van den A.

    2014-01-01

    The European project MultiSward studied the appreciation of different functions of grasslands by European stakeholders. This paper describes the importance of grasslands for stakeholders in Ireland. Ireland currently has approximately 4.6 million ha of grassland, which is 90% of the total utilized

  6. Predation drives nesting success in moist highland grasslands: the ...

    African Journals Online (AJOL)

    By focusing on process-oriented data rather than inventory-type data, this study provides a robust understanding of the effects of agricultural management on grassland bird reproductive output in the moist highland grasslands (MHGs) of South Africa. Four-hundred and four nests of 12 grassland-breeding bird species were ...

  7. COENOLOGICAL SHIFT FOLLOWING FERTILIZATION IN MEDITERRANEAN GRASSLAND

    Directory of Open Access Journals (Sweden)

    ALESSANDRO SERAFINI SAULI

    2006-05-01

    Full Text Available In Rome both meadows of CentraI-European affinity and Mediterranean dry grasslands are presento We studied a site (Parco Regionale Urbano de] Pineto in Rome with very diverse vegetation, where species belonging to both coenologica] groups oceur. Wc fertilized a grassland with a combination of phosphorus (P and nitrogen (N. After fertilization diagDostie species of Helianthemetea guttati (Thcrophytes dccrease while species of MolinioArrhenatheretea (Hemicriptophytes increase. In a climate as that of Rome, transition between Mediterranean (with summer drought and Central European (without summer drought, nutrients availability modulates the distribution of vegetation Classes with respectively Mediterranean or Central-Europe affinities.

  8. Radioecological sensitivity of permanent grasslands

    International Nuclear Information System (INIS)

    Besson, Benoit

    2009-01-01

    The project 'SENSIB' of the Institute for Radiological Protection and Nuclear Safety (IRSN) aims at characterizing and classifying parameters with significant impact on the transfer of radioactive contaminants in the environment. This thesis is focused on permanent grassland areas. Its objectives are the analysis of the activity variations of two artificial radionuclides ( 137 Cs and 90 Sr) in the chain from soil to dairy products as well as the categorization of ecological and anthropogenic parameters, which determine the sensitivity of the studied area. For this study, in situ sampling is carried out in 15 farms in 3 different French regions (Charente, Puy-de-Dome and Jura). The sampling sites are chosen according to their natural variations (geology, altitude and climate) and the soil types. Additionally to the radiologic measurements, geographic, soil and vegetation data as well as data concerning cattle-rearing and cheese manufacturing processes are gathered. From the soil to the grass vegetation, 137 Cs transfer factors vary between 3 x 10-3 and 148 x 10-3 Bq kg-1 (dry weight) per Bq kg-1 (dry weight) (N = 73). Theses transfer factors are significantly higher in the Puy-de-Dome region than in the Jura region. The 137 Cs transfer factor from cattle feed to milk varies from 5.9 x 10-3 to 258 x 10-3 Bq kg-1 (fresh weight) per Bq kg-1 (dry weight) (N = 28). Statistically, it is higher in the Charente region. Finally, the 90 Sr transfer factor from milk to cheese ranges from 3.9 to 12.1. The studied site with the highest factor is the Jura (N = 25). The link between milk and dairy products is the stage with the most 137 Cs and 90 Sr transfers. A nonlinear approach based on a discretization method of the transfer factor with multiple comparison tests admits a classification of the sensitivity factors from soil to grass vegetation. We can determine 20 factors interfering in the 137 Cs transfer into the vegetation, for instance, the clay rate of the soils or a marker

  9. Sustaining the grassland sea: Regional perspectives on identifying, protecting and restoring the Sky Island region's most intact grassland valley landscapes

    Science.gov (United States)

    Gitanjali S. Bodner; Peter Warren; David Gori; Karla Sartor; Steven Bassett

    2013-01-01

    Grasslands of the Sky Islands region once covered over 13 million acres in southeastern Arizona and adjacent portions of New Mexico, Sonora, and Chihuahua. Attempts to evaluate current ecological conditions suggest that approximately two thirds of these remain as intact or restorable grassland habitat. These grasslands provide watershed services such as flood control...

  10. Cell size is positively correlated between different tissues in passerine birds and amphibians, but not necessarily in mammals

    OpenAIRE

    Kozłowski, J.; Czarnołęski, M.; François-Krassowska, A.; Maciak, S.; Pis, T.

    2010-01-01

    We examined cell size correlations between tissues, and cell size to body mass relationships in passerine birds, amphibians and mammals. The size correlated highly between all cell types in birds and amphibians; mammalian tissues clustered by size correlation in three tissue groups. Erythrocyte size correlated well with the volume of other cell types in birds and amphibians, but poorly in mammals. In birds, body mass correlated positively with the size of all cell types including erythrocytes...

  11. Five new feather mites of the subfamily Pterodectinae (Acariformes: Astigmata: Proctophyllodidae) from passerines and hummingbirds (Aves) of Brazil.

    Science.gov (United States)

    Hernandes, Fabio Akashi; Pedroso, Luiz Gustavo A; Oniki-Willis, Yoshika

    2016-09-06

    Five new species of feather mites (Proctophyllodidae: Pterodectinae) are described from passerines and hummingbirds of Brazil: Amerodectes longifuscus sp. nov. from Poospiza lateralis (Nordmann, 1835) (Passeriformes: Emberizidae), A. vireonis sp. nov. from Vireo olivaceus (Linnaeus, 1766) (Passeriformes: Vireonidae), Tyrannidectes synallaxis sp. nov. from Synallaxis ruficapilla Vieillot, 1819 (Passeriformes: Furnariidae), Trochilodectes willisi sp. nov. from Phaethornis eurynome (Lesson, 1832) (Apodiformes: Trochilidae), and Xynonodectes phaethornis sp. nov. from Ph. pretrei (Lesson & Delattre, 1839) (Apodiformes: Trochilidae).

  12. Grasslands feeling the heat: The effects of elevated temperatures on a subtropical grassland

    Directory of Open Access Journals (Sweden)

    Rowan D. Buhrmann

    2016-12-01

    Conclusions: OTCs can simulate realistic increases of air temperature in subtropical grasslands. Graminoids and shrubs appear to benefit from elevated temperatures whilst forbs decrease in abundance, possibly through competition and/or direct physiological effects.

  13. Migratory status is not related to the susceptibility to HPAIV H5N1 in an insectivorous passerine species.

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    Donata Kalthoff

    Full Text Available Migratory birds have evolved elaborate physiological adaptations to travelling, the implications for their susceptibility to avian influenza are however unknown. Three groups of stonechats (Saxicola torquata from (I strongly migrating, (II weakly migrating and (III non-migrating populations were experimentally infected with HPAIV H5N1. The different bird groups of this insectivorous passerine species were infected in autumn, when the migrating populations clearly exhibit migratory restlessness. Following infection, all animals succumbed to the disease from 3 through 7 days post inoculation. Viral shedding, antigen distribution in tissues, and survival time did not differ between the three populations. However, notably, endothelial tropism of the HPAIV infection was exclusively seen in the group of resident birds. In conclusion, our data document for the first time the high susceptibility of an insectivorous passerine species to H5N1 infection, and the epidemiological role of these passerine birds is probably limited due to their high sensitivity to HPAIV H5N1 infection. Despite pronounced inherited differences in migratory status, the groups were generally indistinguishable in their susceptibility, survival time, clinical symptoms and viral shedding. Nevertheless, the migratory status partly influenced pathogenesis in the way of viral tropism.

  14. Proactive conservation management of an island-endemic bird species in the face of global change

    Science.gov (United States)

    Morrison, S.A.; Sillett, T. Scott; Ghalambor, Cameron K.; Fitzpatrick, J.W.; Graber, D.M.; Bakker, V.J.; Bowman, R.; Collins, C.T.; Collins, P.W.; Delaney, K.S.; Doak, D.F.; Koenig, Walter D.; Laughrin, L.; Lieberman, A.A.; Marzluff, J.M.; Reynolds, M.D.; Scott, J.M.; Stallcup, J.A.; Vickers, W.; Boyce, W.M.

    2011-01-01

    Biodiversity conservation in an era of global change and scarce funding benefits from approaches that simultaneously solve multiple problems. Here, we discuss conservation management of the island scrub-jay (Aphelocoma insularis), the only island-endemic passerine species in the continental United States, which is currently restricted to 250-square-kilometer Santa Cruz Island, California. Although the species is not listed as threatened by state or federal agencies, its viability is nonetheless threatened on multiple fronts. We discuss management actions that could reduce extinction risk, including vaccination, captive propagation, biosecurity measures, and establishing a second free-living population on a neighboring island. Establishing a second population on Santa Rosa Island may have the added benefit of accelerating the restoration and enhancing the resilience of that island's currently highly degraded ecosystem. The proactive management framework for island scrub-jays presented here illustrates how strategies for species protection, ecosystem restoration, and adaptation to and mitigation of climate change can converge into an integrated solution. ?? 2011 by American Institute of Biological Sciences. All rights reserved.

  15. On the stability of mixed grasslands

    NARCIS (Netherlands)

    Schulte, R.P.O.

    2001-01-01

    Recent years have seen a renewed interest in the use of white clover (Trifolium repens) in grasslands, as a more sustainable alternative to fertiliser nitrogen inputs. However, mixtures of grasses and white clover have frequently been associated with unstable and hence unreliable herbage

  16. Purpose and Need for a Grassland Assessment

    Science.gov (United States)

    Deborah M. Finch; Cathy W. Dahms

    2004-01-01

    This report is volume 1 of an ecological assessment of grassland ecosystems in the Southwestern United States, and it is one of a series of planned publications addressing major ecosystems of the Southwest. The first assessment, General Technical Report RM-GTR- 295, An Assessment of Forest Ecosystem Health in the Southwest (by Dahms and Geils, technical editors,...

  17. [Spatiotemporal characteristics of MODIS NDVI in Hulunber Grassland].

    Science.gov (United States)

    Zhang, Hong-Bin; Yang, Gui-Xia; Wu, Wen-Bin; Li, Gang; Chen, Bao-Rui; Xin, Xiao-Ping

    2009-11-01

    Time-series MODIS NDVI datasets from 2000 to 2008 were used to study the spatial change trend, fluctuation degree, and occurrence time of the annual NDVImax of four typical grassland types, i.e., lowland meadow, temperate steppe, temperate meadow steppe, and upland meadow, in Hulunber Grassland. In 2000-2008, the vegetation in Hulunber Grassland presented an obvious deterioration trend. The mean annual NDVImax of the four grassland types had a great fluctuation, especially in temperate steppe where the maximum change in the mean value of annual NDVImax approximated to 50%. As for the area change of different grade grasslands, the areas with NDVImax between 0.4 and 1 accounted for about 91% of the total grassland area, which suggested the good vegetation coverage in the Grassland. However, though the areas with NDVImax values in (0.4, 0.8) showed an increasing trend, the areas with NDVImax values in (0.2, 0.4) and (0.8, 1) decreased greatly in the study period. Overall, the deteriorating grassland took up about 66.25% of the total area, and the restoring grassland took the rest. There was about 62.85% of the grassland whose NDVImax occurred between the 193rd day and the 225th day in each year, indicating that this period was the most important vegetation growth season in Hulunber Grassland.

  18. Modeling the grazing effect on dry grassland carbon cycling with modified Biome-BGC grazing model

    Science.gov (United States)

    Luo, Geping; Han, Qifei; Li, Chaofan; Yang, Liao

    2014-05-01

    Identifying the factors that determine the carbon source/sink strength of ecosystems is important for reducing uncertainty in the global carbon cycle. Arid grassland ecosystems are a widely distributed biome type in Xinjiang, Northwest China, covering approximately one-fourth the country's land surface. These grasslands are the habitat for many endemic and rare plant and animal species and are also used as pastoral land for livestock. Using the modified Biome-BGC grazing model, we modeled carbon dynamics in Xinjiang for grasslands that varied in grazing intensity. In general, this regional simulation estimated that the grassland ecosystems in Xinjiang acted as a net carbon source, with a value of 0.38 Pg C over the period 1979-2007. There were significant effects of grazing on carbon dynamics. An over-compensatory effect in net primary productivity (NPP) and vegetation carbon (C) stock was observed when grazing intensity was lower than 0.40 head/ha. Grazing resulted in a net carbon source of 23.45 g C m-2 yr-1, which equaled 0.37 Pg in Xinjiang in the last 29 years. In general, grazing decreased vegetation C stock, while an increasing trend was observed with low grazing intensity. The soil C increased significantly (17%) with long-term grazing, while the soil C stock exhibited a steady trend without grazing. These findings have implications for grassland ecosystem management as it relates to carbon sequestration and climate change mitigation, e.g., removal of grazing should be considered in strategies that aim to increase terrestrial carbon sequestrations at local and regional scales. One of the greatest limitations in quantifying the effects of herbivores on carbon cycling is identifying the grazing systems and intensities within a given region. We hope our study emphasizes the need for large-scale assessments of how grazing impacts carbon cycling. Most terrestrial ecosystems in Xinjiang have been affected by disturbances to a greater or lesser extent in the past

  19. An inventory of wetland non-passerine birds along a southeastern Brazilian coastal area

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    D.C. Tavares

    2013-07-01

    Full Text Available This paper presents the list of non-passerine birds of coastal environments of the Quissama municipality, northern Rio de Janeiro State, southeastern Brazil. The surveys were conducted monthly between June 2011 and May 2012. Additional ad libitum observations were made between February 2008 and July 2012. We recorded 76 waterbird species of 15 families, of which Scolopacidae was the most representative, with 15 species. The high Nearctic shorebird species richness observed in coastal lagoons in Quissama (17 species is an evidence of the important role of the region as staging site for migratory birds at national level. Also, nine of the species recorded are threatened at regional and one is threatened at national level. It should be emphasized that three species considered locally extinct in the municipality of Rio de Janeiro, the most extensively surveyed area in the State, were recorded in the present study. Additionally, we present a high number of previously unrecorded species in northern Rio de Janeiro, and report the first documented record of Stercorarius pomarinus in Rio de Janeiro State. The region has a notorious Waterbird richness including endangered and migratory species, when compared to other coastal areas of the state.

  20. Selection for rapid embryo development correlates with embryo exposure to maternal androgens among passerine birds.

    Science.gov (United States)

    Schwabl, Hubert; Palacios, Maria G; Martin, Thomas E

    2007-08-01

    Greater offspring predation favors evolution of faster development among species. We hypothesized that greater offspring predation exerts selection on mothers to increase levels of anabolic androgens in egg yolks to achieve faster development. Here, we tested whether (1) concentrations of yolk androgens in passerine species were associated with offspring predation and (2) embryo and nestling development rates were associated with yolk androgen concentrations. We examined three androgens that increase in potency along the synthesis pathway: androstenedione (A(4)) to testosterone (T) to 5 alpha -dihydrotestosterone (5 alpha -DHT). Concentrations of none of these steroids were related to clutch size; only A(4) was allometrically related to egg volume. Species that experience greater predation showed higher yolk concentrations of T and 5 alpha -DHT. Higher concentrations of T and particularly 5 alpha -DHT were strongly correlated with faster development during the embryo period and less so during the nestling period. Development rates were most strongly correlated with 5 alpha -DHT, suggesting that potency increases along the androgen synthesis pathway and that effects are mediated by the androgen receptor pathway. These results are consistent with the hypothesis that selection for faster development by time-dependent offspring mortality may be achieved epigenetically by varying embryo exposure to maternal anabolic steroids.

  1. Metal accumulation and performance of nestlings of passerine bird species at an urban brownfield site

    International Nuclear Information System (INIS)

    Hofer, Charles; Gallagher, Frank J.; Holzapfel, Claus

    2010-01-01

    The use of passerine species as bioindicators of metal bioaccumulation is often underutilized when examining the wildlife habitat value of polluted sites. In this study we tested feathers of nestlings of two common bird species (house wren and American robin) for accumulation of Pb, Zn, As, Cr, Cu, Fe in comparison of a polluted, urban brownfield with a rural, unpolluted site. House wren nestlings at the study site accumulated significantly greater concentrations of all target metals except Zn. At the polluted site we found significant species differences of metal concentrations in feathers, with house wrens accumulating greater concentrations of Pb, Fe, and Zn but slightly lesser accumulations of Cr and Cu than American robins. Although house wren nestlings demonstrated significant accumulation of metals, these concentrations showed little effect on size metrics or fledge rates during the breeding season compared to nestlings from the control site. - Nestlings of birds in an urban brownfield accumulated soil contaminants but did not show signs of reduced breeding success or growth.

  2. Metal accumulation and performance of nestlings of passerine bird species at an urban brownfield site

    Energy Technology Data Exchange (ETDEWEB)

    Hofer, Charles; Gallagher, Frank J. [Department of Ecology, Evolution and Natural Resources, Rutgers, the State University of New Jersey, 14 College Farm Rd., New Brunswick, NJ 08901-8551 (United States); Holzapfel, Claus, E-mail: holzapfe@andromeda.rutgers.ed [Department of Biological Sciences, Rutgers, the State University of New Jersey, Newark, 195 University Ave., Newark, NJ 07102-1811 (United States)

    2010-05-15

    The use of passerine species as bioindicators of metal bioaccumulation is often underutilized when examining the wildlife habitat value of polluted sites. In this study we tested feathers of nestlings of two common bird species (house wren and American robin) for accumulation of Pb, Zn, As, Cr, Cu, Fe in comparison of a polluted, urban brownfield with a rural, unpolluted site. House wren nestlings at the study site accumulated significantly greater concentrations of all target metals except Zn. At the polluted site we found significant species differences of metal concentrations in feathers, with house wrens accumulating greater concentrations of Pb, Fe, and Zn but slightly lesser accumulations of Cr and Cu than American robins. Although house wren nestlings demonstrated significant accumulation of metals, these concentrations showed little effect on size metrics or fledge rates during the breeding season compared to nestlings from the control site. - Nestlings of birds in an urban brownfield accumulated soil contaminants but did not show signs of reduced breeding success or growth.

  3. Geographical variation in egg mass and egg content in a passerine bird.

    Directory of Open Access Journals (Sweden)

    Suvi Ruuskanen

    Full Text Available Reproductive, phenotypic and life-history traits in many animal and plant taxa show geographic variation, indicating spatial variation in selection regimes. Maternal deposition to avian eggs, such as hormones, antibodies and antioxidants, critically affect development of the offspring, with long-lasting effects on the phenotype and fitness. Little is however known about large-scale geographical patterns of variation in maternal deposition to eggs. We studied geographical variation in egg components of a passerine bird, the pied flycatcher (Ficedula hypoleuca, by collecting samples from 16 populations and measuring egg and yolk mass, albumen lysozyme activity, yolk immunoglobulins, yolk androgens and yolk total carotenoids. We found significant variation among populations in most egg components, but ca. 90% of the variation was among individuals within populations. Population however explained 40% of the variation in carotenoid levels. In contrast to our hypothesis, we found geographical trends only in carotenoids, but not in any of the other egg components. Our results thus suggest high within-population variation and leave little scope for local adaptation and genetic differentiation in deposition of different egg components. The role of these maternally-derived resources in evolutionary change should be further investigated.

  4. No Evidence for Pre-Copulatory Sexual Selection on Sperm Length in a Passerine Bird

    Science.gov (United States)

    Lifjeld, Jan T.; Laskemoen, Terje; Kleven, Oddmund; Pedersen, A. Tiril M.; Lampe, Helene M.; Rudolfsen, Geir; Schmoll, Tim; Slagsvold, Tore

    2012-01-01

    There is growing evidence that post-copulatory sexual selection, mediated by sperm competition, influences the evolution of sperm phenotypes. Evidence for pre-copulatory sexual selection effects on sperm traits, on the other hand, is rather scarce. A recent paper on the pied flycatcher, Ficedula hypoleuca, reported phenotypic associations between sperm length and two sexually selected male traits, i.e. plumage colour and arrival date, thus invoking pre-copulatory sexual selection for longer sperm. We were unable to replicate these associations with a larger data set from the same and two additional study populations; sperm length was not significantly related to either male plumage colour or arrival date. Furthermore, there was no significant difference in sperm length between populations despite marked differences in male plumage colour. We also found some evidence against the previously held assumption of longer sperm being qualitatively superior; longer sperm swam at the same speed as shorter sperm, but were less able to maintain speed over time. We argue that both empirical evidence and theoretical considerations suggest that the evolution of sperm morphology is not primarily associated with pre-copulatory sexual selection on male secondary sexual traits in this or other passerine bird species. The relatively large between-male variation in sperm length in this species is probably due to relaxed post-copulatory sexual selection. PMID:22384277

  5. Divergent primary moult-A rare moult sequence among Western Palaearctic passerines.

    Directory of Open Access Journals (Sweden)

    Yosef Kiat

    Full Text Available Wing morphology strongly affects flight performance which may consequently decline during feather moult due to the creation of feather gaps in the wing. Hence, the size and shape of moult-related wing gap may directly affect flight capacity. Here I examined the rare divergent primary moult sequence compared to the more common descendant moult sequence. In the divergent moult, the focus of primary moult is shifted from P1 (primary feather numbered descendantly to another primary between P2 and P5, and then primaries are moulted in two concurrent waves, one descendant and the other ascendant. The result of this rare moult sequence is the splitting of the wing gap to two smaller gaps. Using a large moult database including 6,763 individuals of 32 Western Palaearctic passerine species, I found evidence of divergent moult only among 27 individuals of 12 species. I examined the speed of wing-feather moult for each individual that moulted divergently compared to a control group of individuals at the same moult stage which moulted following the common descending sequence. The results indicate that the sequence of primary moult and moult speed are correlated. Individuals which moulted divergently moulted their primaries with higher moult speed than descendant moulters. The applicability of this study is weakened by the dearth of moult data, thus making it difficult to draw conclusions for a large range of species. Ornithologists and bird ringers are therefore encouraged to collect more basic moult data during their field study.

  6. Evolution of iris colour in relation to cavity nesting and parental care in passerine birds.

    Science.gov (United States)

    Davidson, Gabrielle L; Thornton, Alex; Clayton, Nicola S

    2017-01-01

    Strong selection pressures are known to act on animal coloration. Although many animals vary in eye colour, virtually no research has investigated the functional significance of these colour traits. Passeriformes have a range of iris colours, making them an ideal system to investigate how and why iris colour has evolved. Using phylogenetic comparative methods, we tested the hypothesis that conspicuous iris colour in passerine birds evolved in response to (a) coordination of offspring care and (b) cavity nesting, two traits thought to be involved in intra-specific gaze sensitivity. We found that iris colour and cooperative offspring care by two or more individuals evolved independently, suggesting that bright eyes are not important for coordinating parental care through eye gaze. Furthermore, we found that evolution between iris colour and nesting behaviour did occur in a dependent manner, but contrary to predictions, transitions to coloured eyes were not more frequent in cavity nesters than non-cavity nesters. Instead, our results indicate that selection away from having bright eyes was much stronger in non-cavity nesters than cavity nesters, perhaps because conspicuous eye coloration in species not concealed within a cavity would be more visible to predators. © 2017 The Authors.

  7. A passerine spreads its tail to facilitate a rapid recovery of its body posture during hovering.

    Science.gov (United States)

    Su, Jian-Yuan; Ting, Shang-Chieh; Chang, Yu-Hung; Yang, Jing-Tang

    2012-07-07

    We demonstrate experimentally that a passerine exploits tail spreading to intercept the downward flow induced by its wings to facilitate the recovery of its posture. The periodic spreading of its tail by the White-eye bird exhibits a phase correlation with both wingstroke motion and body oscillation during hovering flight. During a downstroke, a White-eye's body undergoes a remarkable pitch-down motion, with the tail undergoing an upward swing. This pitch-down motion becomes appropriately suppressed at the end of the downstroke; the bird's body posture then recovers gradually to its original status. Employing digital particle-image velocimetry, we show that the strong downward flow induced by downstroking the wings serves as an external jet flow impinging upon the tail, providing a depressing force on the tail to counteract the pitch-down motion of the bird's body. Spreading of the tail enhances a rapid recovery of the body posture because increased forces are experienced. The maximum force experienced by a spread tail is approximately 2.6 times that of a non-spread tail.

  8. No evidence for pre-copulatory sexual selection on sperm length in a passerine bird.

    Directory of Open Access Journals (Sweden)

    Jan T Lifjeld

    Full Text Available There is growing evidence that post-copulatory sexual selection, mediated by sperm competition, influences the evolution of sperm phenotypes. Evidence for pre-copulatory sexual selection effects on sperm traits, on the other hand, is rather scarce. A recent paper on the pied flycatcher, Ficedula hypoleuca, reported phenotypic associations between sperm length and two sexually selected male traits, i.e. plumage colour and arrival date, thus invoking pre-copulatory sexual selection for longer sperm. We were unable to replicate these associations with a larger data set from the same and two additional study populations; sperm length was not significantly related to either male plumage colour or arrival date. Furthermore, there was no significant difference in sperm length between populations despite marked differences in male plumage colour. We also found some evidence against the previously held assumption of longer sperm being qualitatively superior; longer sperm swam at the same speed as shorter sperm, but were less able to maintain speed over time. We argue that both empirical evidence and theoretical considerations suggest that the evolution of sperm morphology is not primarily associated with pre-copulatory sexual selection on male secondary sexual traits in this or other passerine bird species. The relatively large between-male variation in sperm length in this species is probably due to relaxed post-copulatory sexual selection.

  9. Scale-dependent mechanisms of habitat selection for a migratory passerine: an experimental approach

    Science.gov (United States)

    Donovan, Therese M.; Cornell, Kerri L.

    2010-01-01

    Habitat selection theory predicts that individuals choose breeding habitats that maximize fitness returns on the basis of indirect environmental cues at multiple spatial scales. We performed a 3-year field experiment to evaluate five alternative hypotheses regarding whether individuals choose breeding territories in heterogeneous landscapes on the basis of (1) shrub cover within a site, (2) forest land-cover pattern surrounding a site, (3) conspecific song cues during prebreeding settlement periods, (4) a combination of these factors, and (5) interactions among these factors. We tested hypotheses with playbacks of conspecific song across a gradient of landscape pattern and shrub density and evaluated changes in territory occupancy patterns in a forest-nesting passerine, the Black-throated Blue Warbler (Dendroica caerulescens). Our results support the hypothesis that vegetation structure plays a primary role during presettlement periods in determining occupancy patterns in this species. Further, both occupancy rates and territory turnover were affected by an interaction between local shrub density and amount of forest in the surrounding landscape, but not by interactions between habitat cues and social cues. Although previous studies of this species in unfragmented landscapes found that social postbreeding song cues played a key role in determining territory settlement, our prebreeding playbacks were not associated with territory occupancy or turnover. Our results suggest that in heterogeneous landscapes during spring settlement, vegetation structure may be a more reliable signal of reproductive performance than the physical location of other individuals.

  10. Energy analysis of various grassland utilisation systems

    Directory of Open Access Journals (Sweden)

    Jozef Ržonca

    2005-01-01

    Full Text Available In 2003 and 2004 was carried out the energy analysis of the different types of permanent grassland utilization on the Hrubý Jeseník locality. There were estimated values of the particular entrances of additional energy. Energy entrances moved according to the pratotechnologies from 2.17 GJ. ha–1 to 22.70 GJ.ha–1. The biggest share on energy entrances had fertilizers. It was 84.93% by the nitrogen fertilisation. The most energy benefit of brutto and nettoenergy was marked by the low intensive utilisation (33.40 GJ.ha–1 NEL and 32.40 GJ.ha–1 NEV on average. The highest value of energy efficiency (13.23% was marked by the low intensive utilization of permanent grassland. By using of higher doses of industrial fertilizers has energy efficiency decreased. From view of energy benefit and intensiveness on energy entrances it appears the most available utilisation of permanent grassland with three cuts per year (first cut on May 31st at the latest, every next after 60 days or two cuts per year (first cut on July 15th, next cuts after 90 days.

  11. The ecological and economic consequences of changing land use in the southern Drakensberg grasslands, South Africa

    Directory of Open Access Journals (Sweden)

    JK Turpie

    2014-05-01

    Full Text Available The grassland biome of the southern Drakensberg region of South Africa is characterized by a relatively rich floral biodiversity, including a high level of endemics.  Land use in the area was traditionally dominated by livestock ranching based mainly on indigenous grassland that conserved biodiversity to some degree.  Currently however, market demands and risk factors are shifting land use in the area to a matrix of beef, cropping, dairy and particularly, towards plantation forestry.  A spreadsheet model was constructed to understand how expected land use conversion will likely influence the biodiversity, and consequently, the total economic value (TEV of the area.  Six scenarios of increasing dairy and forestry intensification were modelled that incorporated biophysical and legal constraints to development.  Results indicate that enhanced development is likely to have significant negative biodiversity impacts including the reduction of the alpha diversity of the indigenous plants in the region, a diminished local invertebrate diversity, an increase in invasions, and could also jeopardize the long term survival of the rare Wattled Crane and Oribi.  Furthermore, while the direct use value derived from agriculture and forestry increases with increasing development, its negative influence on the indirect value of water runoff, by far the greatest value of the area, is sufficient to potentially offset the benefits.  Other major direct-use, indirect-use, option and existence values are also considered.

  12. Matrix matters: differences of grand skink metapopulation parameters in native tussock grasslands and exotic pasture grasslands.

    Directory of Open Access Journals (Sweden)

    Konstanze Gebauer

    Full Text Available Modelling metapopulation dynamics is a potentially very powerful tool for conservation biologists. In recent years, scientists have broadened the range of variables incorporated into metapopulation modelling from using almost exclusively habitat patch size and isolation, to the inclusion of attributes of the matrix and habitat patch quality. We investigated the influence of habitat patch and matrix characteristics on the metapopulation parameters of a highly endangered lizard species, the New Zealand endemic grand skink (Oligosoma grande taking into account incomplete detectability. The predictive ability of the developed zxmetapopulation model was assessed through cross-validation of the data and with an independent data-set. Grand skinks occur on scattered rock-outcrops surrounded by indigenous tussock (bunch and pasture grasslands therefore implying a metapopulation structure. We found that the type of matrix surrounding the habitat patch was equally as important as the size of habitat patch for estimating occupancy, colonisation and extinction probabilities. Additionally, the type of matrix was more important than the physical distance between habitat patches for colonisation probabilities. Detection probability differed between habitat patches in the two matrix types and between habitat patches with different attributes such as habitat patch composition and abundance of vegetation on the outcrop. The developed metapopulation models can now be used for management decisions on area protection, monitoring, and the selection of translocation sites for the grand skink. Our study showed that it is important to incorporate not only habitat patch size and distance between habitat patches, but also those matrix type and habitat patch attributes which are vital in the ecology of the target species.

  13. SOWING GRASSLANDS – EFFICIENT SOLUTION FOR ZOOTEHNICAL PRODUCTION

    Directory of Open Access Journals (Sweden)

    VALENTINA OFELIA ROBESCU

    2008-05-01

    Full Text Available Recruitment is critical for the maintenance of plant populations and community diversity, but sexual regeneration is considered to be infrequent in climatically harsh habitats such as sub alpine grasslands. For this reasons it is very important to improve the grassland. In this paper we study the interaction among milk production, fertilizations and flower composition in sub alpine grasslands. The agrochemical indicators are important because they influence the pasture value and at the final the milk production.

  14. Effects of grassland management on the emission of methane from grassland on peat soils

    Energy Technology Data Exchange (ETDEWEB)

    Oenema, O. [Department of Soil Science and Plant Nutrition, Wageningen Agricultural University, Wageningen (Netherlands)

    1995-12-31

    The aim of the project on the title subject is to provide insight into the major controlling factors that contribute to the net exchange rates of methane (CH4) between grassland and atmosphere, and to provide quantitative net CH4 emission rates. Net CH4 emissions have been monitored with vented closed flux chambers on both intensively managed grasslands and grasslands in a nature preserve on peat soil in the Netherlands. Net CH4 emissions from intensively managed grasslands (Zegveld, Netherlands) were low in the period January-December 1994, in general in the range of -0.2 to 0.2 mg CH4 m{sup -2} d{sup -1}. Only in the relatively warm summer of 1994, consumption of atmospheric CH4 of about 0.4 mg m{sup -2} d{sup -1} was measured. Effects of ground water level in the range of 30-60 cm below surface were very small. There were also no clear effects of nitrogen fertilization and grazing versus mowing on CH4 emission from the soil. Net CH4 emissions from three extensively managed grasslands in a nature preserve (Nieuwkoopse Plassen area in the Netherlands) ranged from 0-215 mg CH4 m{sup -2} d{sup -1} in the period January 1994-June 1995. Differences between the three sites were quite large, as were the spatial variations at each of the sites. The results presented here indicate that a shift of intensively managed peat grasslands into more natural ecosystems will significantly increase the contribution of Dutch peat soils to the total CH4 emission. refs.

  15. Novel plumage aberrations in Paraguayan non-Passerine Birds, and the definition of a new plumage aberration unique to Psittacidae

    Directory of Open Access Journals (Sweden)

    Paul Smith

    2017-07-01

    Full Text Available Anomalous plumage colourations are reported for three species of non-passerine birds from Paraguay, Limpkin (Aramaus guarauna; Aramidae, Nanday Parakeet (Nandayus nenday; Psittacidae, and the Little Woodpecker (Veniliornis passerinus; Picidae. A leucistic Limpkin is the first published report of a colour anomaly for the family Aramidae. The colour aberration in N. nenday is hypothesised to be a result of an excess of red psittacofulvin pigments, which are unique to the Psittacidae. Although the mechanisms causing this colour aberration remain unknown, we suggest the term psittacofulvism for the phenotypic effect observed.

  16. Delimiting areas of endemism through kernel interpolation.

    Science.gov (United States)

    Oliveira, Ubirajara; Brescovit, Antonio D; Santos, Adalberto J

    2015-01-01

    We propose a new approach for identification of areas of endemism, the Geographical Interpolation of Endemism (GIE), based on kernel spatial interpolation. This method differs from others in being independent of grid cells. This new approach is based on estimating the overlap between the distribution of species through a kernel interpolation of centroids of species distribution and areas of influence defined from the distance between the centroid and the farthest point of occurrence of each species. We used this method to delimit areas of endemism of spiders from Brazil. To assess the effectiveness of GIE, we analyzed the same data using Parsimony Analysis of Endemism and NDM and compared the areas identified through each method. The analyses using GIE identified 101 areas of endemism of spiders in Brazil GIE demonstrated to be effective in identifying areas of endemism in multiple scales, with fuzzy edges and supported by more synendemic species than in the other methods. The areas of endemism identified with GIE were generally congruent with those identified for other taxonomic groups, suggesting that common processes can be responsible for the origin and maintenance of these biogeographic units.

  17. Delimiting areas of endemism through kernel interpolation.

    Directory of Open Access Journals (Sweden)

    Ubirajara Oliveira

    Full Text Available We propose a new approach for identification of areas of endemism, the Geographical Interpolation of Endemism (GIE, based on kernel spatial interpolation. This method differs from others in being independent of grid cells. This new approach is based on estimating the overlap between the distribution of species through a kernel interpolation of centroids of species distribution and areas of influence defined from the distance between the centroid and the farthest point of occurrence of each species. We used this method to delimit areas of endemism of spiders from Brazil. To assess the effectiveness of GIE, we analyzed the same data using Parsimony Analysis of Endemism and NDM and compared the areas identified through each method. The analyses using GIE identified 101 areas of endemism of spiders in Brazil GIE demonstrated to be effective in identifying areas of endemism in multiple scales, with fuzzy edges and supported by more synendemic species than in the other methods. The areas of endemism identified with GIE were generally congruent with those identified for other taxonomic groups, suggesting that common processes can be responsible for the origin and maintenance of these biogeographic units.

  18. Environmental Monitoring of Endemic Cholera

    Science.gov (United States)

    ElNemr, W.; Jutla, A. S.; Constantin de Magny, G.; Hasan, N. A.; Islam, M.; Sack, R.; Huq, A.; Hashem, F.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat. Since Vibrio cholerae, the causative agent of the disease, is autochthonous to riverine, estuarine, and coastal waters, it is unlikely the bacteria can be eradicated from its natural habitat. Prediction of disease, in conjunction with preventive vaccination can reduce the prevalence rate of a disease. Understanding the influence of environmental parameters on growth and proliferation of bacteria is an essential first step in developing prediction methods for outbreaks. Large scale geophysical variables, such as SST and coastal chlorophyll, are often associated with conditions favoring growth of V. cholerae. However, local environmental factors, meaning biological activity in ponds from where the bulk of populations in endemic regions derive water for daily usage, are either neglected or oversimplified. Using data collected from several sites in two geographically distinct locations in South Asia, we have identified critical local environmental factors associated with cholera outbreak. Of 18 environmental variables monitored for water sources in Mathbaria (a coastal site near the Bay of Bengal) and Bakergonj (an inland site) of Bangladesh, water depth and chlorophyll were found to be important factors associated with initiation of cholera outbreaks. Cholera in coastal regions appears to be related to intrusion. However, monsoonal flooding creates conditions for cholera epidemics in inland regions. This may be one of the first attempts to relate in-situ environmental observations with cholera. We anticipate that it will be useful for further development of prediction models in the resource constrained regions.

  19. Blood parasites shape extreme major histocompatibility complex diversity in a migratory passerine.

    Science.gov (United States)

    Biedrzycka, Aleksandra; Bielański, Wojciech; Ćmiel, Adam; Solarz, Wojciech; Zając, Tadeusz; Migalska, Magdalena; Sebastian, Alvaro; Westerdahl, Helena; Radwan, Jacek

    2018-06-01

    Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorphic genes of the vertebrate major histocompatibility complex (MHC). Although MHC proteins are crucial in pathogen recognition, it is still poorly understood how pathogen-mediated selection promotes and maintains MHC diversity, and especially so in host species with highly duplicated MHC genes. Sedge warblers (Acrocephalus schoenobaenus) have highly duplicated MHC genes, and using data from high-throughput MHC genotyping, we were able to investigate to what extent avian malaria parasites explain temporal MHC class I supertype fluctuations in a long-term study population. We investigated infection status and infection intensities of two different strains of Haemoproteus, that is avian malaria parasites that are known to have significant fitness consequences in sedge warblers. We found that prevalence of avian malaria in carriers of specific MHC class I supertypes was a significant predictor of their frequency changes between years. This finding suggests that avian malaria infections partly drive the temporal fluctuations of the MHC class I supertypes. Furthermore, we found that individuals with a large number of different supertypes had higher resistance to avian malaria, but there was no evidence for an optimal MHC class I diversity. Thus, the two studied malaria parasite strains appear to select for a high MHC class I supertype diversity. Such selection may explain the maintenance of the extremely high number of MHC class I gene copies in sedge warblers and possibly also in other passerines where avian malaria is a common disease. © 2018 John Wiley & Sons Ltd.

  20. Use of captive starlings to determine effects of pollutants on passerine reproduction

    Science.gov (United States)

    Grue, C.E.; Christian, C.L.; Lamb, D.W.; Kenaga, E.E.

    1981-01-01

    Three reproductive trials were conducted to develop techniques for propagation of captive starlings (Stumus vulgaris) which could determine the effects of environmental contaminants on passerine reproduction. Trials were conducted during the spring of 1979 in five adjacent 2.4 by 3 by 12-m outdoor wire pens containing four or ten pairs of starlings, a similar number of nest boxes, perches, water, commercial turkey starter, and alfalfa hay as nesting material. Nestling diets consisted of combinations of Nebraska Brand bird of prey diet, live or frozen mealworms (Tenebrio molitor) and crickets (Acheta domestica), or live earthworms (Pheretima sp.). Starlings reproduced successfully when the number of breeding pairs per pen was reduced from ten to four. The average clutch sizes for each pen (4.3 to 4.9) were similar to those reported for wild starlings. Hatching (60 to 90.4 percent) and fledging (0 to 100 percent) success varied among pens. The fledging success was greatest in the pens which received the most diverse nestling diets: Nebraska Brand diet plus frozen or live mealworms and crickets. Whether the insects were presented alive or frozen appeared to have little effect on the reproductive success. The starlings did not consume or carry earthworms to their young. The body weights of 20-day-old nestlings raised in captivity (X=73.9 g) were similar to those of starlings in the wild. The use of single pairs per pen may eliminate problems in presentation of nestling diets due to asynchrony in breeding between pairs and excessive interactions among individuals, which may interfere with parental care. The starling appears to be an excellent model for examining the effects of environmental contaminants on the reproduction of songbirds in captivity.

  1. Variation in maternal effects and embryonic development rates among passerine species.

    Science.gov (United States)

    Martin, Thomas E; Schwabl, Hubert

    2008-05-12

    Embryonic development rates are reflected by the length of incubation period in birds, and these vary substantially among species within and among geographical regions. The incubation periods are consistently shorter in North America (Arizona study site) than in tropical (Venezuela) and subtropical (Argentina) South America based on the study of 83 passerine species in 17 clades. Parents, mothers in particular, may influence incubation periods and resulting offspring quality through proximate pathways, while variation in maternal strategies among species can result from selection by adult and offspring mortality. Parents of long-lived species, as is common in the tropics and subtropics, may be under selection to minimize costs to themselves during incubation. Indeed, time spent incubating is often lower in the tropical and subtropical species than the related north temperate species, causing cooler average egg temperatures in the southern regions. Decreased egg temperatures result in longer incubation periods and reflect a cost imposed on offspring by parents because energy cost to the embryo and risk of offspring predation are both increased. Mothers may adjust egg size and constituents as a means to partially offset such costs. For example, reduced androgen concentrations in egg yolks may slow development rates, but may enhance offspring quality through physiological trade-offs that may be particularly beneficial in longer-lived species, as in the tropics and subtropics. We provide initial data to show that yolks of tropical birds contain substantially lower concentrations of growth-promoting androgens than north temperate relatives. Thus, maternal (and parental) effects on embryonic development rates may include contrasting and complementary proximate influences on offspring quality and deserve further field study among species.

  2. Potential ecotoxicological significance of elevated concentrations of strontium in eggshells of passerine birds

    Science.gov (United States)

    Mora, Miguel A.; Taylor, Robert J.; Brattin, Bryan L.

    2007-01-01

    We investigated the occurrence and potential ecotoxicological significance of elevated concentrations of strontium (Sr) in eggshells of nine passerine birds from four regions in Arizona. Concentrations of Sr in eggshells ranged from 70 to 1360 µg g−1 dry weight (overall mean  =  684 ± 345 SD µg g−1 dw) for the four regions. 23% of the eggshells had Sr concentrations greater than 1000 µg g−1 dw. To our knowledge, these are among the highest levels of Sr that have been reported in bird eggshells in North America. Of the nine species, Brown-headed Cowbirds (Molothrus ater) had the greatest concentrations of Sr. There was a significant positive correlation between Sr and calcium (Ca), and between barium (Ba) and Ca. Ca, Sr, and Ba interact with each other and can exert similar chemical and pharmacological effects. Mean (n ≥ 3) eggshell∶egg ratios for Sr varied with species and ranged from 6.1∶1 to 40.2∶1; ratios for individual eggs reached 92.7∶1. Mean Sr/Ca values ranged from 1.3 × 10−3 to 3.0 × 10−3 and mean eggshell thickness ranged from 83 ± 6 to 120 ± 9 µm for all species. Eggshell thickness was not significantly correlated with Sr for any species but tended to increase with Sr concentrations. We postulate that high concentrations of Sr in the shell could affect later-stage embryos by possible interference with Ca metabolism and bone growth, resulting in reduced hatching success and potential minor beak deformities.

  3. Seasonal and geographical variation in heat tolerance and evaporative cooling capacity in a passerine bird.

    Science.gov (United States)

    Noakes, Matthew J; Wolf, Blair O; McKechnie, Andrew E

    2016-03-01

    Intraspecific variation in avian thermoregulatory responses to heat stress has received little attention, despite increasing evidence that endothermic animals show considerable physiological variation among populations. We investigated seasonal (summer versus winter) variation in heat tolerance and evaporative cooling in an Afrotropical ploceid passerine, the white-browed sparrow-weaver (Plocepasser mahali; ∼ 47 g) at three sites along a climatic gradient with more than 10 °C variation in mid-summer maximum air temperature (Ta). We measured resting metabolic rate (RMR) and total evaporative water loss (TEWL) using open flow-through respirometry, and core body temperature (Tb) using passive integrated transponder tags. Sparrow-weavers were exposed to a ramped profile of progressively higher Ta between 30 and 52 °C to elicit maximum evaporative cooling capacity (N=10 per site per season); the maximum Ta birds tolerated before the onset of severe hyperthermia (Tb ≈ 44 °C) was considered to be their hyperthermia threshold Ta (Ta,HT). Our data reveal significant seasonal acclimatisation of heat tolerance, with a desert population of sparrow-weavers reaching significantly higher Ta in summer (49.5 ± 1.4 °C, i.e. higher Ta,HT) than in winter (46.8 ± 0.9 °C), reflecting enhanced evaporative cooling during summer. Moreover, desert sparrow-weavers had significantly higher heat tolerance and evaporative cooling capacity during summer compared with populations from more mesic sites (Ta,HT=47.3 ± 1.5 and 47.6 ± 1.3 °C). A better understanding of the contributions of local adaptation versus phenotypic plasticity to intraspecific variation in avian heat tolerance and evaporative cooling capacity is needed for modelling species' responses to changing climates. © 2016. Published by The Company of Biologists Ltd.

  4. Antioxidant defenses predict long-term survival in a passerine bird.

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    Nicola Saino

    2011-05-01

    Full Text Available Normal and pathological processes entail the production of oxidative substances that can damage biological molecules and harm physiological functions. Organisms have evolved complex mechanisms of antioxidant defense, and any imbalance between oxidative challenge and antioxidant protection can depress fitness components and accelerate senescence. While the role of oxidative stress in pathogenesis and aging has been studied intensively in humans and model animal species under laboratory conditions, there is a dearth of knowledge on its role in shaping life-histories of animals under natural selection regimes. Yet, given the pervasive nature and likely fitness consequences of oxidative damage, it can be expected that the need to secure efficient antioxidant protection is powerful in molding the evolutionary ecology of animals. Here, we test whether overall antioxidant defense varies with age and predicts long-term survival, using a wild population of a migratory passerine bird, the barn swallow (Hirundo rustica, as a model.Plasma antioxidant capacity (AOC of breeding individuals was measured using standard protocols and annual survival was monitored over five years (2006-2010 on a large sample of selection episodes. AOC did not covary with age in longitudinal analyses after discounting the effect of selection. AOC positively predicted annual survival independently of sex. Individuals were highly consistent in their relative levels of AOC, implying the existence of additive genetic variance and/or environmental (including early maternal components consistently acting through their lives.Using longitudinal data we showed that high levels of antioxidant protection positively predict long-term survival in a wild animal population. Present results are therefore novel in disclosing a role for antioxidant protection in determining survival under natural conditions, strongly demanding for more longitudinal eco-physiological studies of life-histories in

  5. External heart deformities in passerine birds exposed to environmental mixtures of polychlorinated biphenyls during development.

    Science.gov (United States)

    DeWitt, Jamie C; Millsap, Deborah S; Yeager, Ronnie L; Heise, Steve S; Sparks, Daniel W; Henshel, Diane S

    2006-02-01

    Necropsy-observable cardiac deformities were evaluated from 283 nestling passerines collected from one reference site and five polychlorinated biphenyl (PCB)-contaminated sites around Bloomington and Bedford, Indiana, USA. Hearts were weighed and assessed on relative scales in three dimensions (height, length, and width) and for externally visible deformities. Heart weights normalized to body weight (heart somatic index) were decreased significantly at the more contaminated sites in both house wren (Troglodytes aedon) and tree swallow (Tachycineta bicolor). Heart somatic indices significantly correlated with log PCB concentrations in Carolina chickadee (Parus carolinesis) and tree swallow and with log 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent values in tree swallow alone. Ventricular length was increased significantly in eastern bluebirds (Sialia sialis) and decreased significantly in Carolina chickadee and tree swallow from contaminated sites versus the reference site. Heart length regressed significantly against the log PCB concentrations (Carolina chickadee and tree swallow) or the square of the PCB concentrations (red-winged blackbird [Agelaius phoeniceus]) in a sibling bird. The deformities that were observed most at the contaminated sites included abnormal tips (pointed, rounded, or flattened), center rolls, macro- and microsurface roughness, ventricular indentations on the ventral or dorsal surface, lateral ventricular notches, visibly thin ventricular walls, and changes in overall heart shape. A pooled heart deformity index regressed significantly against the logged contaminant concentrations for all species except red-winged blackbird. These results indicate that developmental changes in heart morphometrics and shape abnormalities are quantifiable and may be sensitive and useful indicators of PCB-related developmental impacts across many avian species.

  6. Variation in maternal effects and embryonic development rates among passerine species

    Science.gov (United States)

    Martin, T.E.; Schwabl, H.

    2008-01-01

    Embryonic development rates are reflected by the length of incubation period in birds, and these vary substantially among species within and among geographical regions. The incubation periods are consistently shorter in North America (Arizona study site) than in tropical (Venezuela) and subtropical (Argentina) South America based on the study of 83 passerine species in 17 clades. Parents, mothers in particular, may influence incubation periods and resulting offspring quality through proximate pathways, while variation in maternal strategies among species can result from selection by adult and offspring mortality. Parents of long-lived species, as is common in the tropics and subtropics, may be under selection to minimize costs to themselves during incubation. Indeed, time spent incubating is often lower in the tropical and subtropical species than the related north temperate species, causing cooler average egg temperatures in the southern regions. Decreased egg temperatures result in longer incubation periods and reflect a cost imposed on offspring by parents because energy cost to the embryo and risk of offspring predation are both increased. Mothers may adjust egg size and constituents as a means to partially offset such costs. For example, reduced androgen concentrations in egg yolks may slow development rates, but may enhance offspring quality through physiological trade-offs that may be particularly beneficial in longer-lived species, as in the tropics and subtropics. We provide initial data to show that yolks of tropical birds contain substantially lower concentrations of growth-promoting androgens than north temperate relatives. Thus, maternal (and parental) effects on embryonic development rates may include contrasting and complementary proximate influences on offspring quality and deserve further field study among species. ?? 2007 The Royal Society.

  7. Seasonal behavioral responses of an arid-zone passerine in a hot environment.

    Science.gov (United States)

    Pattinson, Nicholas B; Smit, Ben

    2017-10-01

    Many arid-zone animals have to forage under extremely hot conditions to maintain water and energy balance. The effect of high air temperatures (T air ) on the behavioral patterns of small endothermic animals-characterized by their high energy and water demands-will provide a valuable framework for understanding species vulnerability to climate warming. We determined the seasonal behavioral responses to changes in T air in a~10-g arid-zone passerine, the rufous-eared warbler (Malcorus pectoralis), in the Karoo semi-desert, South Africa. Rufous-eared warblers showed significant temperature-dependence in their behavior in summer, but not in winter. During summer, the warblers frequently experienced T air exceeding 40°C in the shade. For all observations 36°C, the warblers showed reductions in preening (40% decrease), foraging effort (56% decrease), and foraging success (15% decrease), as well as a significant increase in time spent engaged in evaporative cooling behavior. Moreover, as T air increased the warblers shifted increasingly off the ground and out of the full sun, into microsites in the shade (131% increase) and in shrubs (23% increase). In this regard, behavior varied seasonally, with the time spent in the shade 23% higher, and foraging effort 28% higher, in summer compared to winter across a range of moderate T air (15-30°C). Our findings emphasize the link between behavior and temperature in small birds inhabiting hot, arid environments, as well as the importance of understanding these responses for predicting biologically meaningful responses (and hence, vulnerability) of arid-zone avian communities to climactic shifts. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines.

    Directory of Open Access Journals (Sweden)

    Justus P Deikumah

    Full Text Available Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L ratios (an indicator of elevated chronic stress to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.

  9. Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines.

    Science.gov (United States)

    Deikumah, Justus P; McAlpine, Clive A; Maron, Martine

    2015-01-01

    Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L) ratios (an indicator of elevated chronic stress) to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.

  10. Evolution of ultraviolet vision in the largest avian radiation - the passerines.

    Science.gov (United States)

    Ödeen, Anders; Håstad, Olle; Alström, Per

    2011-10-24

    Interspecific variation in avian colour vision falls into two discrete classes: violet sensitive (VS) and ultraviolet sensitive (UVS). They are characterised by the spectral sensitivity of the most shortwave sensitive of the four single cones, the SWS1, which is seemingly under direct control of as little as one amino acid substitution in the cone opsin protein. Changes in spectral sensitivity of the SWS1 are ecologically important, as they affect the abilities of birds to accurately assess potential mates, find food and minimise visibility of social signals to predators. Still, available data have indicated that shifts between classes are rare, with only four to five independent acquisitions of UV sensitivity in avian evolution. We have classified a large sample of passeriform species as VS or UVS from genomic DNA and mapped the evolution of this character on a passerine phylogeny inferred from published molecular sequence data. Sequencing a small gene fragment has allowed us to trace the trait changing from one stable state to another through the radiation of the passeriform birds. Their ancestor is hypothesised to be UVS. In the subsequent radiation, colour vision changed between UVS and VS at least eight times. The phylogenetic distribution of SWS1 cone opsin types in Passeriformes reveals a much higher degree of complexity in avian colour vision evolution than what was previously indicated from the limited data available. Clades with variation in the colour vision system are nested among clades with a seemingly stable VS or UVS state, providing a rare opportunity to understand how an ecologically important trait under simple genetic control may co-evolve with, and be stabilised by, associated traits in a character complex.

  11. Evolution of ultraviolet vision in the largest avian radiation - the passerines

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    Håstad Olle

    2011-10-01

    Full Text Available Abstract Background Interspecific variation in avian colour vision falls into two discrete classes: violet sensitive (VS and ultraviolet sensitive (UVS. They are characterised by the spectral sensitivity of the most shortwave sensitive of the four single cones, the SWS1, which is seemingly under direct control of as little as one amino acid substitution in the cone opsin protein. Changes in spectral sensitivity of the SWS1 are ecologically important, as they affect the abilities of birds to accurately assess potential mates, find food and minimise visibility of social signals to predators. Still, available data have indicated that shifts between classes are rare, with only four to five independent acquisitions of UV sensitivity in avian evolution. Results We have classified a large sample of passeriform species as VS or UVS from genomic DNA and mapped the evolution of this character on a passerine phylogeny inferred from published molecular sequence data. Sequencing a small gene fragment has allowed us to trace the trait changing from one stable state to another through the radiation of the passeriform birds. Their ancestor is hypothesised to be UVS. In the subsequent radiation, colour vision changed between UVS and VS at least eight times. Conclusions The phylogenetic distribution of SWS1 cone opsin types in Passeriformes reveals a much higher degree of complexity in avian colour vision evolution than what was previously indicated from the limited data available. Clades with variation in the colour vision system are nested among clades with a seemingly stable VS or UVS state, providing a rare opportunity to understand how an ecologically important trait under simple genetic control may co-evolve with, and be stabilised by, associated traits in a character complex.

  12. Modeling the flocking propensity of passerine birds in two Neotropical habitats.

    Science.gov (United States)

    Pomara, Lars Y; Cooper, Robert J; Petit, Lisa J

    2007-08-01

    We examined the importance of mixed-species flock abundance, individual bird home range size, foraging height, and foraging patch characteristics in predicting the propensity for five Neotropical passerine bird species (Slaty Antwren, Myrmotherula schisticolor; Golden-crowned Warbler, Basileuterus culicivorus; Slate-throated Redstart, Myioborus miniatus; Wilson's Warbler, Wilsonia pusilla; and Black-and-white Warbler, Mniotilta varia) to forage within flocks, rather than solitarily. We used study plots in primary mid-elevation forest and in shade coffee fields in western Panama. We expected that all species would spend as much time as possible flocking, but that the social and environmental factors listed above would limit compatibility between flock movements and individual bird movements, explaining variability in flocking propensity both within and among species. Flocking propensity was well predicted by home range size and flock abundance together, for four of the five species. While flock abundance was uniform across plots, home range sizes varied among species and plots, so that home range size appeared to be the principle factor limiting flocking propensity. Estimates of flock abundance were still required, however, for calculating flocking propensity values. Foraging height and patch characteristics slightly improved predictive ability for the remaining species, M. miniatus. In general, individual birds tended to join flocks whenever one was available inside their home range, regardless of a flock's specific location within the home range. Flocking propensities of individual species were lower in shade coffee fields than in forests, and probably vary across landscapes with variations in habitat. This variability affects the stability and species composition of flocks, and may affect survival rates of individual species.

  13. Leptin affects life history decisions in a passerine bird: a field experiment.

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    Mare Lõhmus

    Full Text Available BACKGROUND: Organisms face trade-offs regarding their life-history strategies, such as decisions of single or multiple broods within a year. In passerines displaying facultative multiple breeding, the probability of laying a second clutch is influenced by several life-history factors. However, information about the mechanistic background of these trade-offs is largely lacking. Leptin is a protein hormone produced by white fat cells, and acts as a signal between peripheral energy depots and the central nervous system. In addition, leptin affects cells at all levels of the reproductive axis and plays a critical role in regulating the allocation of metabolic energy to reproduction. As such, it is possible that leptin levels influence the decision of whether or not to invest time and energy into a second clutch. Accordingly, we expect a treatment with exogenous leptin to result in an increased number of second broods. METHODOLOGY/PRINCIPAL FINDINGS: At a later stage during the first brood, female great tits were treated either with long-term leptin-filled cholesterol pellets (the experimental birds or with pellets containing only cholesterol (the control birds. We found that leptin-treated females were significantly more likely to have a second brood and that the earlier females were more likely to lay a second clutch than the late females. CONCLUSIONS/SIGNIFICANCE: As both timing of first brood and treatment with leptin were important in the decision of having multiple broods, the trade-offs involved in the breeding strategy most likely depend on multiple factors. Presumably leptin has evolved as a signal of energy supply status to regulate the release of reproductive hormones so that reproduction is coordinated with periods of sufficient nutrients. This study investigated the role of leptin as a mediator between energy resources and reproductive output, providing a fundamentally new insight into how trade-offs work on a functional basis.

  14. Passerine migrant stopover duration and spatial behaviour at an urban stopover site

    Science.gov (United States)

    Seewagen, Chad L.; Slayton, Eric J.; Guglielmo, Christopher G.

    2010-09-01

    Migration routes of many Nearctic-Neotropical landbirds pass through the most urbanized regions of North America. Migrants are known to use urban habitats as stopover sites and often occur in cities at exceptional density; yet knowledge of migrant behaviour and ecology in such places is surprisingly limited. We radio-tracked ovenbirds ( Seiurus aurocapillus) during stopovers in a New York City park to obtain some of the first detailed information on how landbird migrants utilize an urban habitat as a stopover site. We examined fine-scale movement patterns, home range sizes, stopover durations, and how arrival condition affected each of these metrics. During both seasons, most birds moved widely throughout the site upon presumed arrival and then either continued migration that night or settled into a more defined area on subsequent days. Area usage varied markedly among individuals during both seasons, ranging 1-16 ha. Stopover durations averaged 3.0 days (range = 1-10 days) during spring and 2.9 days (range = 1-14 days) during autumn. Spatial behaviours and stopover durations were not influenced by arrival condition during spring, and during autumn only movement rates and displacement distances were significantly (negatively) condition-related. Our findings do not support previous assumptions that urban stopover habitats are only used by migrants briefly in times of urgency when alternatives are unavailable. At least half of the birds we studied stopped over for multiple days during both seasons, and bird movements were indicative of an ability to search for, locate, and occupy suitable micro-sites. Ovenbird behaviour in our study site was similar in many ways to what has been observed in recent telemetry studies of ovenbirds and other passerine migrants at various non-urban stopover sites.

  15. Arthropods and passerine birds in coniferous forest. The impact of acidification and needle-loss

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, B. [Goeteborg Univ., Dept. of Zoology, Sect. of Animal Ecology, Goeteborg (Sweden)

    1995-12-31

    The micro-habitat structure on coniferous trees changes as a result of needle-loss. This structural change in the vegetation may affect arthropods living in spruce Picea abies by indirect mechanisms, e.g. altered relations between prey and predators. The impact of acidification and needle-loss on some tree-living arthropods and passerine birds is reviewed. New information about the taxonomic composition of spiders in relation to needle density in a field experiments is reported. The main combined findings from the review and field experiments are: 1) Acid precipitation may be toxic because of high H{sup +} concentrations. However, simulated acid rain (pH 4.0) did not reduce the growth rate of a spruce-living spider. There is a present no evidence of toxic effect on arthropods at this level of pH. 2) Experiments in the field and laboratory and data from natural populations suggested that spruce-living arthropods are affected by the needle density of branches. These data showed a positive correlation between needle density and spider abundance. However, a large-scale field experiment could not confirm this relationship. 3) The interaction between bird predation and needle density was examined in a large-scale field experiment. There were strong negative effects of bird predation on arthropod abundance. Moreover, the taxonomic composition among spiders changed as a result of bird predation: raptorial spiders increased their relative abundance whereas sheetweb spiders decreased their relative abundance when bird predation was excluded. There were also some cases of bird predation/needle density interactions. In the absence of bird predation, the needle density affected the spider size distribution: large spiders were more common on needle-sparse branches than on needle-dens ones. The species composition was affected by similar interactions, e.g. bird predation effects on crab spiders (Thomisidae) were found on needle-sparse branches only. (Abstract Truncated)

  16. Shifts in species interactions due to the evolution of functional differences between endemics and non-endemics: an endemic syndrome hypothesis.

    Directory of Open Access Journals (Sweden)

    Courtney E Gorman

    Full Text Available Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic, here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change.

  17. Distinguishing Intensity Levels of Grassland Fertilization Using Vegetation Indices

    Directory of Open Access Journals (Sweden)

    Jens L. Hollberg

    2017-01-01

    Full Text Available Monitoring the reaction of grassland canopies on fertilizer application is of major importance to enable a well-adjusted management supporting a sustainable production of the grass crop. Up to date, grassland managers estimate the nutrient status and growth dynamics of grasslands by costly and time-consuming field surveys, which only provide low temporal and spatial data density. Grassland mapping using remotely-sensed Vegetation Indices (VIs has the potential to contribute to solving these problems. In this study, we explored the potential of VIs for distinguishing five differently-fertilized grassland communities. Therefore, we collected spectral signatures of these communities in a long-term fertilization experiment (since 1941 in Germany throughout the growing seasons 2012–2014. Fifteen VIs were calculated and their seasonal developments investigated. Welch tests revealed that the accuracy of VIs for distinguishing these grassland communities varies throughout the growing season. Thus, the selection of the most promising single VI for grassland mapping was dependent on the date of the spectra acquisition. A random forests classification using all calculated VIs reduced variations in classification accuracy within the growing season and provided a higher overall precision of classification. Thus, we recommend a careful selection of VIs for grassland mapping or the utilization of temporally-stable methods, i.e., including a set of VIs in the random forests algorithm.

  18. Cattle slurry on grassland - application methods and nitrogen use efficiency

    NARCIS (Netherlands)

    Lalor, S.T.J.

    2014-01-01

    Cattle slurry represents a significant resource on grassland-based farming systems. The objective of this thesis was to investigate and devise cattle slurry application methods and strategies that can be implemented on grassland farms to improve the efficiency with which nitrogen (N) in

  19. Ecological transition in Arizona's subalpine and montane grasslands

    Science.gov (United States)

    Michael R. White

    2000-01-01

    Important components of Southwest forest ecosystem are subalpine and montane grassland communities, Grassland communities provide habitat diversity for wildlife, forage for domestic livestock and wildlife, and contribute to the visual quality of an area. The objectives of this research were to determine if: 1) vegetation attributes and soil-surface cover variables of...

  20. Influence of density on the seasonal utilization of broad grassland ...

    African Journals Online (AJOL)

    We monitored seasonal use of grassland types by white rhinos at two sites within the Hluhluwe iMfolozi Park (HiP). Thirty-two rhinos were removed from one site to reduce rhino density. Seasonal use of grassland types was similar at both sites, but differed to what a previous study reported. This was likely due to higher food ...

  1. A taxonomic, functional, and phylogenetic perspective on the community assembly of passerine birds along an elevational gradient in southwest China.

    Science.gov (United States)

    He, Xuelian; Luo, Kang; Brown, Calum; Lin, Luxiang

    2018-03-01

    Integrating multiple facets of biodiversity to describe spatial and temporal distribution patterns is one way of revealing the mechanisms driving community assembly. We assessed the species, functional, and phylogenetic composition and structure of passerine bird communities along an elevational gradient both in wintering and breeding seasons in the Ailao Mountains, southwest China, in order to identify the dominant ecological processes structuring the communities and how these processes change with elevation and season. Our research confirms that the highest taxonomic diversity, and distinct community composition, was found in the moist evergreen broadleaf forest at high elevation in both seasons. Environmental filtering was the dominant force at high elevations with relatively cold and wet climatic conditions, while the observed value of mean pairwise functional and phylogenetic distances of low elevation was constantly higher than expectation in two seasons, suggested interspecific competition could play the key role at low elevations, perhaps because of relative rich resource result from complex vegetation structure and human-induced disturbance. Across all elevations, there was a trend of decreasing intensity of environmental filtering whereas increasing interspecific competition from wintering season to breeding season. This was likely due to the increased resource availability but reproduction-associated competition in the summer months. In general, there is a clear justification for conservation efforts to protect entire elevational gradients in the Ailao Mountains, given the distinct taxonomic, functional, and phylogenetic compositions and also elevational migration pattern in passerine bird communities.

  2. In silico peptide-binding predictions of passerine MHC class I reveal similarities across distantly related species, suggesting convergence on the level of protein function

    DEFF Research Database (Denmark)

    Follin, Elna; Karlsson, Maria; Lundegaard, Claus

    2013-01-01

    The major histocompatibility complex (MHC) genes are the most polymorphic genes found in the vertebrate genome, and they encode proteins that play an essential role in the adaptive immune response. Many songbirds (passerines) have been shown to have a large number of transcribed MHC class I genes...

  3. Non-endemic cases of lymphatic filariasis.

    Science.gov (United States)

    Jones, Robert T

    2014-11-01

    Several cases of lymphatic filariasis (LF) have been reported in non-endemic countries due to travellers, military personnel and expatriates spending time in and returning from endemic areas, as well as immigrants coming from these regions. These cases are reviewed to assess the scale and context of non-endemic presentations and to consider the biological factors underlying their relative paucity. Cases reported in the English, French, Spanish and Portuguese literature during the last 30 years were examined through a search of the PubMed, ProMED-mail and TropNet resources. The literature research revealed 11 cases of lymphatic filariasis being reported in non-endemic areas. The extent of further infections in recent migrants to non-endemic countries was also revealed through the published literature. The life-cycle requirements of Wuchereria and Brugia species limit the extent of transmission of LF outside of tropical regions. However, until elimination, programmes are successful in managing the disease, there remains a possibility of low rates of infection being reported in non-endemic areas, and increased international travel can only contribute to this phenomenon. Physicians need to be aware of the signs and symptoms of lymphatic filariasis, and infection should be considered in the differential diagnosis of people with a relevant travel history. © 2014 John Wiley & Sons Ltd.

  4. A conservation assessment of the terrestrial invertebrate fauna of Mkambati Nature Reserve in the Pondoland Centre of Endemism

    Directory of Open Access Journals (Sweden)

    Michelle L. Hamer

    2017-05-01

    Full Text Available Mkambati Nature Reserve (NR falls within the Pondoland Centre of Endemism, which is part of the Maputaland-Pondoland-Albany global biodiversity hotspot. The biodiversity status of this area is based largely on its flora, and the invertebrates are poorly known. The area is under threat from various proposed developments. We surveyed 14 orders in three invertebrate phyla at 26 sites with two main objectives: (1 to assess the fauna in terms of conservation value, and, (2 to identify habitats and sites of conservation concern. From the survey, 3231 samples were sent for identification and 425 species were identified. A minimum of 18 new species were confirmed. Mkambati NR shows exceptional diversity for molluscs (Gastropoda, 51 species, bees (Apoidea, 48 species and true bugs (Heteroptera, 65 species. At least 43 species collected from the Reserve are South African endemics, 31 have a restricted distribution within South Africa and 18 are only known from the Reserve itself. Conservation implications: The authors provide the first assessment of the invertebrate fauna of the Mkambati NR, which indicates that it is a rich and important fauna. The results highlight the need to consider invertebrates in other biodiversity assessments in the Pondoland region. In terms of habitats, for both forest and grassland there was a large difference in the invertebrate communities at different sites, even over relatively short distances in grassland; shared habitat attributes clustered sites with more similar communities, for example, rocky ledges or the sea shore. All forest patches are a priority for protection.

  5. Effects of Government Grassland Conservation Policy on Household Livelihoods and Dependence on Local Grasslands: Evidence from Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Bingzhen Du

    2016-12-01

    Full Text Available Grassland degradation intensifies human-environment conflicts and adversely affects local residents’ livelihoods. To reduce grassland degradation in Inner Mongolia, China, the government has enforced (since 1998 a series of grassland conservation and management policies that restrict the use of grasslands. To ease the impact on the residents’ livelihoods, the national and regional governments have offered a series of top-down arrangements to stimulate sustainable use of the grasslands. Simultaneously, local households spontaneously developed bottom-up countermeasures. To determine the effects of these processes, we interviewed members of 135 households using a mix of qualitative and quantitative methods. We analyzed the effects on household dependence on local grasslands and on perceptions of the future of grassland use. Our findings show that the implementation of the grassland conservation policies significantly affected household livelihoods, which in turn affected household use of natural assets (primarily the land, their agricultural assets (farming and grazing activities and their financial assets (income and consumption, resulting in fundamental transformation of their lifestyles. The households developed adaptation measures to account for the dependence of their livelihood on local ecosystems by initializing strategies, such as seeking off-farm work, leasing pasture land, increasing purchases of fodder for stall-fed animals and altering their diet and fuel consumption to compensate for their changing livelihoods.

  6. Indirect Effects of Energy Development in Grasslands

    Science.gov (United States)

    Duquette, Cameron Albert

    Grassland landscapes in North America are undergoing rapid industrialization due to energy development facilitated by the growing popularity of fracking and horizontal drilling technology. Each year over 3 million hectares are lost from grassland and shrubland habitats to well infrastructure. Direct footprints from energy infrastructure cause impacts to vegetation cover, available cattle forage, carbon sequestration potential, and usable space for wildlife. However, legacy effects from well construction and noise pollution, light pollution, and altered viewsheds have the potential to impact areas beyond this direct footprint, causing additive and persistent changes to nearby grassland function. While these additional areas may be small on a well pad basis, they may have substantial cumulative impacts over time. To investigate these effects via a diversity of mechanisms, we studied the seasonal habitat selection of northern bobwhite (Colinus virginianus, hereafter bobwhite) in an energy-producing landscape to evaluate space use patterns relative to energy infrastructure. Habitat selection was modeled in the breeding and nonbreeding season using resource Utilization functions (RUFs). We then investigated patterns of vegetation, arthropod, and soil characteristics surrounding well pads to assess small scale environmental gradients extending away from drilling pads via a combination of multivariate and univariate techniques (i.e., Nonmetric dimensional scaling and ANOVA). We found minimal avoidance of energy structures by quail, suggesting a tolerance of moderate development levels. All small-scale effects studied except for soil moisture were impacted at the pad itself (P < 0.01). Off-pad impacts to arthropod abundance and biomass were spatially limited to areas close to pads, while vegetation cover was typically lower than the surrounding habitat beyond 10 m of pads. Soil surface temperature was higher at distances close to well pads, and soil moisture was not

  7. The role of grasslands in food security and climate change.

    Science.gov (United States)

    O'Mara, F P

    2012-11-01

    Grasslands are a major part of the global ecosystem, covering 37 % of the earth's terrestrial area. For a variety of reasons, mostly related to overgrazing and the resulting problems of soil erosion and weed encroachment, many of the world's natural grasslands are in poor condition and showing signs of degradation. This review examines their contribution to global food supply and to combating climate change. Grasslands make a significant contribution to food security through providing part of the feed requirements of ruminants used for meat and milk production. Globally, this is more important in food energy terms than pig meat and poultry meat. Grasslands are considered to have the potential to play a key role in greenhouse gas mitigation, particularly in terms of global carbon storage and further carbon sequestration. It is estimated that grazing land management and pasture improvement (e.g. through managing grazing intensity, improved productivity, etc) have a global technical mitigation potential of almost 1·5 Gt CO(2) equivalent in 2030, with additional mitigation possible from restoration of degraded lands. Milk and meat production from grassland systems in temperate regions has similar emissions of carbon dioxide per kilogram of product as mixed farming systems in temperate regions, and, if carbon sinks in grasslands are taken into account, grassland-based production systems can be as efficient as high-input systems from a greenhouse gas perspective. Grasslands are important for global food supply, contributing to ruminant milk and meat production. Extra food will need to come from the world's existing agricultural land base (including grasslands) as the total area of agricultural land has remained static since 1991. Ruminants are efficient converters of grass into humanly edible energy and protein and grassland-based food production can produce food with a comparable carbon footprint as mixed systems. Grasslands are a very important store of carbon, and

  8. Clinical significance of neurocysticercosis in endemic villages

    International Nuclear Information System (INIS)

    García, H.H.; Gilman, R.H.; Tsang, V.C.W.; Gonzalez, A.E.

    1997-01-01

    Cerebral cysticercosis is the main cause of late-onset epilepsy in most developing countries. Data on the neuroepidemiology of cysticercosis in endemic populations is scarce. In an endemic village on the northern coast of Peru, 49 individuals with neurological symptomatology (41 epileptic and 8 non-epileptic) were screened for antibodies to Taenia solium, using a serum electroimmuno transfer blot assay. Fifteen subjects were seropositive, 14 (34%) of those with epilepsy but only one (13%) of those who were non-epileptic. A history of passing proglottides was associated with positive serology. Thirteen of the 15 seropositive individuals underwent cerebral computed tomography; only 7 (54%) were abnormal. A randomly selected sample of 20 pigs from the village was also tested, and 6 (30%) were seropositive. This study demonstrated the importance of cysticercosis in the aetiology of epilepsy in endemic villages and the close relationship between porcine and human infection

  9. Antimycobacterial and antimalarial activities of endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from Brazil.

    Science.gov (United States)

    Ferreira, Mariana C; Cantrell, Charles L; Wedge, David E; Gonçalves, Vívian N; Jacob, Melissa R; Khan, Shabana; Rosa, Carlos A; Rosa, Luiz H

    2017-10-01

    Endophytic fungi, present mainly in the Ascomycota and Basidiomycota phyla, are associated with different plants and represent important producers of bioactive natural products. Brazil has a rich biodiversity of plant species, including those reported as being endemic. Among the endemic Brazilian plant species, Vellozia gigantea (Velloziaceae) is threatened by extinction and is a promising target to recover endophytic fungi. The present study focused on bioprospecting of bioactive compounds of the endophytic fungi associated with V. gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil. The capability of 285 fungal isolates to produce antimicrobial and antimalarial activities was examined. Fungi were grown at solid-state fermentation to recover their crude extracts in dichloromethane. Bioactive extracts were analysed by chromatographic fractionation and NMR and displayed compounds with antimicrobial, antimycobacterial, and antimalarial activities. Five fungi produced antimicrobial and antimalarial compounds. Extracts of Diaporthe miriciae showed antifungal, antibacterial, and antimalarial activities; Trichoderma effusum displayed selective antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare; and three Penicillium species showed antibacterial activity. D. miriciae extract contained highly functionalised secondary metabolites, yielding the compound epoxycytochalasin H with high antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum, with an IC50 approximately 3.5-fold lower than that with chloroquine. Our results indicate that V. gigantea may represent a microhabitat repository hotspot of potential fungi producers of bioactive compounds and suggest that endophytic fungal communities might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.

  10. Transitions between Andean and Amazonian centers of endemism in the radiation of some arboreal rodents

    Science.gov (United States)

    2013-01-01

    Background The tropical Andes and Amazon are among the richest regions of endemism for mammals, and each has given rise to extensive in situ radiations. Various animal lineages have radiated ex situ after colonizing one of these regions from the other: Amazonian clades of dendrobatid frogs and passerine birds may have Andean ancestry, and transitions from the Amazon to Andes may be even more common. To examine biogeographic transitions between these regions, we investigated the evolutionary history of three clades of rodents in the family Echimyidae: bamboo rats (Dactylomys-Olallamys-Kannabateomys), spiny tree-rats (Mesomys-Lonchothrix), and brush-tailed rats (Isothrix). Each clade is distributed in both the Andes and Amazonia, and is more diverse in the lowlands. We used two mitochondrial (cyt-b and 12S) and three nuclear (GHR, vWF, and RAG1) markers to reconstruct their phylogenetic relationships. Tree topologies and ancestral geographic ranges were then used to determine whether Andean forms were basal to or derived from lowland radiations. Results Four biogeographic transitions are identified among the generic radiations. The bamboo rat clade unambiguously originated in the Amazon ca. 9 Ma, followed by either one early transition to the Andes (Olallamys) and a later move to the Amazon (Dactylomys), or two later shifts to the Andes (one in each genus). The Andean species of both Dactylomys and Isothrix are sister to their lowland species, raising the possibility that highland forms colonized the Amazon Basin. However, uncertainty in their reconstructed ancestral ranges obscures the origin of these transitions. The lone Andean species of Mesomys is confidently nested within the lowland radiation, thereby indicating an Amazon-to-Andes transition ca. 2 Ma. Conclusions Differences in the timing of these biogeographic transitions do not appear to explain the different polarities of these trees. Instead, even within the radiation of a single family, both Andean and

  11. Side-specific effect of yolk testosterone elevation on second-to-fourth digit ratio in a wild passerine

    Science.gov (United States)

    Nagy, Gergely; Blázi, György; Hegyi, Gergely; Török, János

    2016-02-01

    Second-to-fourth digit ratio is a widely investigated sexually dimorphic morphological trait in human studies and could reliably indicate the prenatal steroid environment. Conducting manipulative experiments to test this hypothesis comes up against ethical limits in humans. However, oviparous tetrapods may be excellent models to experimentally investigate the effects of prenatal steroids on offspring second-to-fourth digit ratio. In this field study, we injected collared flycatcher ( Ficedula albicollis) eggs with physiological doses of testosterone. Fledglings from eggs with elevated yolk testosterone, regardless of their sex, had longer second digits on their left feet than controls, while the fourth digit did not differ between groups. Therefore, second-to-fourth digit ratio was higher in the testosterone-injected group, but only on the left foot. This is the first study which shows experimentally that early testosterone exposure can affect second-to-fourth digit ratio in a wild population of a passerine bird.

  12. Measurement of grassland evaporation using a surface-layer ...

    African Journals Online (AJOL)

    Measurement of grassland evaporation using a surface-layer scintillometer. ... Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search ... of soil heat flux and net irradiance, evaporation rates were calculated as a residual of the ...

  13. Ecological mechanisms underlying arthropod species diversity in grasslands.

    Science.gov (United States)

    Joern, Anthony; Laws, Angela N

    2013-01-01

    Arthropods are an important component of grassland systems, contributing significantly to biodiversity and ecosystem structure and function. Climate, fire, and grazing by large herbivores are important drivers in grasslands worldwide. Arthropod responses to these drivers are highly variable and clear patterns are difficult to find, but responses are largely indirect with respect to changes in resources, species interactions, habitat structure, and habitat heterogeneity resulting from interactions among fire, grazing, and climate. Here, we review these ecological mechanisms influencing grassland arthropod diversity. We summarize hypotheses describing species diversity at local and regional scales and then discuss specific factors that may affect arthropod diversity in grassland systems. These factors include direct and indirect effects of grazing, fire, and climate, species interactions, above- and belowground interactions, and landscape-level effects.

  14. Soil Organic Carbon Responses to Forest Expansion on Mountain Grasslands

    DEFF Research Database (Denmark)

    Guidi, Claudia

    . Changes in labile soil C were assessed by carbohydrate and thermal analyses of soil samples and fractions. Forest expansion on mountain grasslands caused a decrease in SOC stocks within the mineral soil. The SOC accumulation within the organic layers following forest establishment could not fully...... and thermally labile to resistant components decreased from grassland to forest successional stages, and corresponded to decreased SOC protection within stable aggregates. This PhD thesis showed that mineral SOC stocks and physically protected SOC fractions decreased following forest expansion on mountain......Grassland abandonment followed by progressive forest expansion is the dominant land-use change in the European Alps. Contrasting trends in soil organic carbon (SOC) stocks have been reported for mountainous regions following forest expansion on grasslands. Moreover, its effects on SOC properties...

  15. Impact intensities of climatic changes on grassland ecosystems in ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-03-22

    Mar 22, 2012 ... Construction of the impact intensity model of climatic changes on grassland ecosystem ... the temperature and rainfall (Sun and Mu, 2011). Thus, the study ... of the equation, the study transformed the measurement unit Mu of.

  16. Biodiversity in temperate European grasslands: origin and conservation.

    OpenAIRE

    Pärtel, Meelis; Bruun, Hans Henrik; Sammul, Marek

    2005-01-01

    Northern Europe is in the forest zone, but wild megaherbivores have maintained grass-dominated vegetation here for the last 1.8 million years. Continuity of the grassland biome through glacialinterglacial cycles and connection to steppe vegetation has resulted in the evolution, immigration, and survival of a large number of grassland species. During the last millennia the effect of wild ungulates has been replaced by domestic grazers and hay making, and the persistence of grasslan...

  17. Methods for evaluation of the invasibility of grasslands

    DEFF Research Database (Denmark)

    Strandberg, M. T.; Strandberg, B.; Erneberg, M.

    The number of non-native plant species in Danish dry acidic grasslands was positively correlated with the cover of disturbance in the form of molehills, anthills, mouseholes and erosion due trampling or digging by large herbivores/livestock. Natural disturbance in acidic grassland ecosystems...... not grazed by livestock therefore is important for the occurrence of non-native species, and probably also for the occurrence of a high native floristic diversity....

  18. PV water pumping systems for grassland and farmland conservation

    OpenAIRE

    Campana, Pietro Elia

    2013-01-01

    Grassland degradation is considered as one of the worst environmental and economic problems in China because of the negative impacts on water and food security. The application of the photovoltaic water pumping (PVWP) technology for irrigation is an innovative and sustainable solution to curb the progress of grassland desertification and to promote the conservation of farmland in remote areas. The combination of PVWP with water saving irrigation techniques and the sustainable management of th...

  19. The Eurasian Dry Grassland Group (EDGG in 2016–2017

    Directory of Open Access Journals (Sweden)

    Venn Stephen

    2018-06-01

    Full Text Available This report summarizes the activities and achievements of the Eurasian Dry Grassland Group (EDGG from mid-2016 through to the end of 2017. During this period, the 13th Eurasian Grassland Conference took place in Sighişoara, Romania, and the 14th conference was held in Riga, Latvia. The 10th EDGG Field Workshop on Biodiversity patterns across a precipitation gradient in the Central Apennine mountains was conducted in the Central Apennines, Italy, this time in addition to multi-scale sampling of vascular plants, bryophytes and lichens, also including one animal group (leaf hoppers. Apart from the quarterly issues of its own electronic journal (Bulletin of the Eurasian Dry Grassland Group, EDGG also finalised five grassland-related Special Features/Issues during the past 1.5 years in the following international journals: Applied Vegetation Science, Biodiversity and Conservation, Phytocoenologia, Tuexenia and Hacquetia. Beyond that, EDGG facilitated various national and supra-national vegetationplot databases of grasslands and established its own specialised database for standardised multi-scale plot data of Palaearctic grasslands (GrassPlot.

  20. Impacts of Future Grassland Changes on Surface Climate in Mongolia

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2013-01-01

    Full Text Available Climate change caused by land use/cover change (LUCC is becoming a hot topic in current global change, especially the changes caused by the grassland degradation. In this paper, based on the baseline underlying surface data of 1993, the predicted underlying surface data which can be derived through overlaying the grassland degradation information to the map of baseline underlying surface, and the atmospheric forcing data of RCP 6.0 from CMIP5, climatological changes caused by future grassland changes for the years 2010–2020 and 2040–2050 with the Weather Research Forecast model (WRF are simulated. The model-based analysis shows that future grassland degradation will significantly result in regional climate change. The grassland degradation in future could lead to an increasing trend of temperature in most areas and corresponding change range of the annual average temperature of −0.1°C–0.4°C, and it will cause a decreasing trend of precipitation and corresponding change range of the annual average precipitation of 10 mm–50 mm. This study identifies lines of evidence for effects of future grassland degradation on regional climate in Mongolia which provides meaningful decision-making information for the development and strategy plan making in Mongolia.

  1. Endemism in the moss flora of North America.

    Science.gov (United States)

    Carter, Benjamin E; Shaw, Blanka; Shaw, A Jonathan

    2016-04-01

    Identifying regions of high endemism is a critical step toward understanding the mechanisms underlying diversification and establishing conservation priorities. Here, we identified regions of high moss endemism across North America. We also identified lineages that contribute disproportionately to endemism and document the progress of efforts to inventory the endemic flora. To understand the documentation of endemic moss diversity in North America, we tabulated species publication dates to document the progress of species discovery across the continent. We analyzed herbarium specimen data and distribution data from the Flora of North America project to delineate major regions of moss endemism. Finally, we surveyed the literature to assess the importance of intercontinental vs. within-continent diversification for generating endemic species. Three primary regions of endemism were identified and two of these were further divided into a total of nine subregions. Overall endemic richness has two peaks, one in northern California and the Pacific Northwest, and the other in the southern Appalachians. Description of new endemic species has risen steeply over the last few decades, especially in western North America. Among the few studies documenting sister species relationships of endemics, recent diversification appears to have played a larger role in western North America, than in the east. Our understanding of bryophyte endemism continues to grow rapidly. Large continent-wide data sets confirm early views on hotspots of endemic bryophyte richness and indicate a high rate of ongoing species discovery in North America. © 2016 Botanical Society of America.

  2. Habitat associations of migrating and overwintering grassland birds in Southern Texas

    Science.gov (United States)

    Igl, Lawrence D.; Ballard, Bart M.

    1999-01-01

    We report on the habitat associations of 21 species of grassland birds overwintering in or migrating through southern Texas, during 1991-1992 and 1992-1993. Ninety percent of our grassland bird observations were made during winter and spring, and only 10% occurred during fall. Grassland species made up a high proportion of the total bird densities in grassland and shrub-grassland habitats, but much lower proportions in the habitats with more woody vegetation. Fewer grassland species were observed in grassland and woodland than in brushland, parkland, and shrub-grassland habitats. Grassland birds generally were found in higher densities in habitats that had woody canopy coverage of < 30%; densities of grassland birds were highest in shrub-grassland habitat and lowest in woodland habitat. Species that are grassland specialists on their breeding grounds tended to be more habitat specific during the nonbreeding season compared to shrub-grassland specialists, which were more general in their nonbreeding-habitat usage. Nonetheless, our data demonstrate that grassland birds occur in a variety of habitats during the nonbreeding season and seem to occupy a broader range of habitats than previously described.

  3. Does Evapotranspiration Increase When Forests are converted to Grasslands?

    Science.gov (United States)

    Varcoe, Robert; Sterling, Shannon

    2017-04-01

    The conversion of forests to grasslands (FGC) is a widespread land cover change (LCC) and is also among the most commonly studied changes with respect to its impact on ET; such research employs a variety of experimental approaches, including, paired catchment (PC), Budyko and land surface models (LSM), and measurement methods, including the catchment water balance (CWB), eddy covariance (EC) and remote sensing (RS). Until recently, there has been consensus in the scientific literature that rates of ET decrease when a forest is converted to grassland; however, this consensus has recently come into question. Williams (2012) applied the Budyko framework to a global network of eddy covariance measurements with the results that grasslands have a 9% greater evaporative index than forests. In addition, HadGEM2, a recent Hadley Centre LSM, produced increased ET in the northern Amazon Basin after simulating global scale tropical deforestation (Brovkin et al., 2015). Here we present an analysis of available estimates of how ET rates change with FGC to increase our understanding of the forest - grassland-ET paradigm. We used two datasets to investigate the impacts land cover change on ET. I compiled a dataset of change in ET with land cover change (ΔETLCC) using published experiments that compare forest and grassland ET under conditions controlled for meteorological and landscape influences. Using the ΔETLCC dataset, we show that, in all cases, forest ET is higher than grassland under controlled conditions. Results suggest that the eddy covariance method measures smaller changes in ET when forests are converted to grasslands, though more data are needed for this result to be statistically significant. Finally, GETA2.0, a new global dataset of annual ET, projects that forest ET is greater than grassland, except at high latitudes and areas where orography influences precipitation (P). The data included in this study represent the data available on forest and grassland ET

  4. Hexabromocyclododecane in terrestrial passerine birds from e-waste, urban and rural locations in the Pearl River Delta, South China: Levels, biomagnification, diastereoisomer- and enantiomer-specific accumulation

    International Nuclear Information System (INIS)

    Sun Yuxin; Luo Xiaojun; Mo Ling; He Mingjing; Zhang Qiang; Chen Shejun; Zou Fasheng; Mai Bixian

    2012-01-01

    Diastereoisomers and enantiomers of hexabromocyclododecane (HBCD) were determined in muscle and stomach contents of three terrestrial passerine birds from e-waste, urban and rural locations in South China. The highest HBCD concentration was found at the urban site, followed by the e-waste site, suggesting that HBCD was linked to urbanization and industrialization, as well as e-waste recycling activities. Trophic magnification for α-HBCD was observed in the terrestrial food chain. Diastereisomeric pattern in birds showed the predominance of α-isomer, with a minor contribution of γ-isomer. The enantiomeric analysis revealed a preferential enrichment of (−)-α-HBCD and (+)-γ-HBCD. The similarity in enantiomeric fractions of HBCD isomers between muscle and stomach contents of birds suggested that dietary uptake may be responsible for the observed nonracemic distribution of HBCD isomers in the studied birds although in vivo enantioselective biotic processes cannot be ruled out. - Highlights: ► HBCD concentrations in three terrestrial passerine birds and their stomach contents were determined. ► Biomagnification and trophic magnification for α-HBCD was found. ► A preferential enrichment of (−)-α-HBCD and (+)-γ-HBCD were found in birds. ► Diet rather than in vivo biotic processes contributed to the observed nonracemic distribution of HBCD isomers. - Enantiomer-specific accumulation of hexabromocyclododecane in terrestrial passerine birds in South China was demonstrated.

  5. Role of Antidesma ghaesembilla Gaertn in Enriching the Depauperate Bird Community in “Cogon” Imperata cylindrica (L. Raeuschel Dominated Grassland in Swidden Vegetation Matrix

    Directory of Open Access Journals (Sweden)

    Alejandro A. Bernardo Jr.

    2017-11-01

    Full Text Available The study was conducted to understand the role of Antidesma ghaesembilla Gaertn in enhancing the avifaunal diversity in Imperata cylindrica (L. Raeuschel dominated grassland patches and to realize the influence of adjacent vegetations on the assemblage of birds that feed on the fruit of this tree. An avifaunal survey was conducted on “Cogon” dominated grassland patches adjacent to selected vegetations such as primary forest, secondary forest and upland agricultural area. A total of 250 birds belonging to 19 species representing ten families were found feeding on the fruits of Antidesma ghaesembilla. The site adjacent to secondary forest has the highest species richness, abundance and diversity index values. This accentuates the combined influence of the open and forest dwelling bird species thriving in the secondary forest. The sites adjacent to the primary forest and to the agricultural area have the same species richness but differ in species composition as reflected by the low similarity index. More forest dwelling bird species were recorded near the forest while more open dwelling bird species were recorded near the agricultural area. This highlights the spillover effect of the adjacent vegetations on the feeding bird assemblage. The presence of several endemic and conservation priority bird species that feed on the fruits of Antidesma ghaesembilla unfolds its important role in avifaunal conservation. Finally, the wide collection of fruit eating bird species attracted to it emphasized its importance in improving the overall avifaunal diversity in Imperata cylindrica dominated grassland patches within the swidden vegetation matrix.

  6. Rapid assessment of endemic bird areas in Michoacan, Mexico

    Science.gov (United States)

    Gilberto Chavez-Leon; Deborah M. Finch

    1999-01-01

    Non-sustainable land use practices in the state of Michoacan, Mexico, have perturbed endemic bird h~bitats for several decades. Endemic birds have a restricted geographic and ecological distribution. This feature makes them suitable to be used as indicators of biological diversity and environmental perturbation. Forty-one Mexican endemic species have been recorded in...

  7. Endemicity of cholera in Nigeria: A mathematical model to ...

    African Journals Online (AJOL)

    The focal point is to investigate the persistent endemic nature of cholera in Nigeria using mathematical model. We found that, there can be no backward bifurcation because there existed only one positive endemic equilibrium. In other words, it is not possible for multiple endemic equilibria to exist if the reproduction number ...

  8. Patterns of distribution and protection status of the endemic ...

    African Journals Online (AJOL)

    1995-06-02

    Jun 2, 1995 ... South Africa contains the majority of southern Africa's endemic mammals and hence is an important ... example of an archaic fauna that has undergone local radia- ... Indeed, only six of South Africa's endemic. R eprodu ced by Sabin et G atew ..... of the endemic flora of this region is renowned (Cowling,.

  9. Endemics and Pseudo-Endemics in Relation to the Distribution Patterns of Indian Pteridophytes

    Directory of Open Access Journals (Sweden)

    C. R. Fraser-Jenkins

    2008-09-01

    Full Text Available Of c. 530 Pteridophytes reported as endemic to the India in recent decades (about half the total number of c. 950-1000 known Indian species, the great bulk are mistaken, particularly those from the Indo-Himalaya. Only 47 endemic Indian ferns, less than 10% of those reported previously, are accepted here. But this figure includes several that are rather doubtfully endemic, mainly due to unresolved taxonomic doubt, or because they may be expected to occur in adjacent Countries. Thus 8 are taxonomically dubious, requiring further study, and a further 7, all from N.E. India, may possibly be expected elsewhere outside India. The c. 483 mistaken pseudo-endemics arose mainly due to naming of erroneous 'new species' thought to be endemic, or due to not knowing the range of species outside political India, combined with insufficient investigative taxonomic research. In the present paper previous reports of endemics are listed and their status is reappraised along with a new list of accepted endemics. Quite opposite to previous conclusions, the great majority of endemic Indian Pteridophytes are peninsular-Indian to south-Indian ferns (27, plus 5 more taxonomically dubious, with far fewer being N.E. Indian (7, all of which may possibly be expected elsewhere outside India and W. Himalayan (2, plus 1 taxonomically dubious; the floristically Malesian Nicobar Islands have (3, plus 2 more taxonomically dubious. These numbers are only to be expected as N.E. India is an intimate part of the Sino-Himalayan and S.E. Asian flora, connected without barriers to Tibet and China or to Myanmar by two mountain chains, while S. India is more isolated geographically since more ancient times and has a partly Malesian fern-flora. Some details of Indian endemics in relation to phytogeographical elements are given. Endemic species: Huperzia - 1, Selaginella - 9, Isoetes - 1, Osmunda - 1, Arthromeris - 1, Phymatosorus - 1, Oreogrammitis - 2, Trichomanes - 1, Pteris - 1, Cyathea

  10. Application of Multi-Source Remote Sensing Image in Yunnan Province Grassland Resources Investigation

    Science.gov (United States)

    Li, J.; Wen, G.; Li, D.

    2018-04-01

    Trough mastering background information of Yunnan province grassland resources utilization and ecological conditions to improves grassland elaborating management capacity, it carried out grassland resource investigation work by Yunnan province agriculture department in 2017. The traditional grassland resource investigation method is ground based investigation, which is time-consuming and inefficient, especially not suitable for large scale and hard-to-reach areas. While remote sensing is low cost, wide range and efficient, which can reflect grassland resources present situation objectively. It has become indispensable grassland monitoring technology and data sources and it has got more and more recognition and application in grassland resources monitoring research. This paper researches application of multi-source remote sensing image in Yunnan province grassland resources investigation. First of all, it extracts grassland resources thematic information and conducts field investigation through BJ-2 high space resolution image segmentation. Secondly, it classifies grassland types and evaluates grassland degradation degree through high resolution characteristics of Landsat 8 image. Thirdly, it obtained grass yield model and quality classification through high resolution and wide scanning width characteristics of MODIS images and sample investigate data. Finally, it performs grassland field qualitative analysis through UAV remote sensing image. According to project area implementation, it proves that multi-source remote sensing data can be applied to the grassland resources investigation in Yunnan province and it is indispensable method.

  11. Therapy of endemic goiter and hypothyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Luft, D.

    1983-09-12

    Successful treatment of endemic goitre depends on the correct diagnosis and the comprehension of the pathophysiologic changes as well. Several criteria, e.g. anamnestic data, general clinical condition, local symptoms and signs, certainty of diagnosis, contraindications, rates of success, and side effects, determine the particular form of therapy (suppression with thyroid hormones, surgical resection, radio-iodine). The decision criteria are discussed. Prophylaxis of recurrent goitre with either thyroid hormones or iodine salts is necessary after successful treatment. Some endemic goitres behave like either hyper- or hypothyroidism. Treatment with thyroid hormones of patients with latent hyperthyroidism is senseless and dangerous, whereas other methods of treatment may be applied. An unequivocal indication for treatment exists in patients with latent hypothyroidism accompanied by goitre, but not in all patients without goitre. Hormonal replacement therapy of manifest hypothydroidism is simple, but long term success is not achieved in all patients.

  12. Therapy of endemic goiter and hypothyroidism

    International Nuclear Information System (INIS)

    Luft, D.

    1983-01-01

    Successful treatment of endemic goitre depends on the correct diagnosis and the comprehension of the pathophysiologic changes as well. Several criteria, e.g. anamnestic data, general clinical condition, local symptoms and signs, certainty of diagnosis, contraindications, rates of success, and side effects, determine the particular form of therapy (suppression with thyroid hormones, surgical resection, radio-iodine). The decision criteria are discussed. Prophylaxis of recurrent goitre with either thyroid hormones or iodine salts is necessary after successful treatment. Some endemic goitres behave like either hyper- or hypothyroidism. Treatment with thyroid hormones of patients with latent hyperthyroidism is senseless and dangerous, whereas other methods of treatment may be applied. An unequivocal indication for treatment exists in patients with laent hypothyroidism accompanied by goitre, but not in all patients without goitre. Hormonal replacement therapy of manifest hypothydroidism is simple, but long term success is not achieved in all patients. (orig.) [de

  13. Incorporating grassland management in a global vegetation model

    Science.gov (United States)

    Chang, Jinfeng; Viovy, Nicolas; Vuichard, Nicolas; Ciais, Philippe; Wang, Tao; Cozic, Anne; Lardy, Romain; Graux, Anne-Isabelle; Klumpp, Katja; Martin, Raphael; Soussana, Jean-François

    2013-04-01

    Grassland is a widespread vegetation type, covering nearly one-fifth of the world's land surface (24 million km2), and playing a significant role in the global carbon (C) cycle. Most of grasslands in Europe are cultivated to feed animals, either directly by grazing or indirectly by grass harvest (cutting). A better understanding of the C fluxes from grassland ecosystems in response to climate and management requires not only field experiments but also the aid of simulation models. ORCHIDEE process-based ecosystem model designed for large-scale applications treats grasslands as being unmanaged, where C / water fluxes are only subject to atmospheric CO2 and climate changes. Our study describes how management of grasslands is included in the ORCHIDEE, and how management affects modeled grassland-atmosphere CO2 fluxes. The new model, ORCHIDEE-GM (Grassland Management) is capable with a management module inspired from a grassland model (PaSim, version 5.0), of accounting for two grassland management practices (cutting and grazing). The evaluation of the results of ORCHIDEE-GM compared with those of ORCHIDEE at 11 European sites equipped with eddy covariance and biometric measurements, show that ORCHIDEE-GM can capture realistically the cut-induced seasonal variation in biometric variables (LAI: Leaf Area Index; AGB: Aboveground Biomass) and in CO2 fluxes (GPP: Gross Primary Productivity; TER: Total Ecosystem Respiration; and NEE: Net Ecosystem Exchange). But improvements at grazing sites are only marginal in ORCHIDEE-GM, which relates to the difficulty in accounting for continuous grazing disturbance and its induced complex animal-vegetation interactions. Both NEE and GPP on monthly to annual timescales can be better simulated in ORCHIDEE-GM than in ORCHIDEE without management. At some sites, the model-observation misfit in ORCHIDEE-GM is found to be more related to ill-constrained parameter values than to model structure. Additionally, ORCHIDEE-GM is able to simulate

  14. Ecology and Conservation of Steppes and Semi-Natural Grasslands

    Directory of Open Access Journals (Sweden)

    Valkó Orsolya

    2016-12-01

    Full Text Available Palaearctic grasslands encompass a diverse variety of habitats, many of high nature value and vulnerability. The main challenges are climate-change, land-use change, agricultural intensification and abandonment. Many measures are in place to address these challenges, through restoration and appropriate management, though more work is necessary. We present eight studies from China/Germany, Greece, Kazakhstan, Russia and Ukraine. The papers cover a wide range of grassland and steppe habitats and cover vegetation ecology, syntaxonomy and zoology. We also conducted a systematic search on steppe and grassland diversity. The greatest number of studies was from China, followed by Germany and England. We conclude that the amount of research being carried out on Eurasian grasslands is inadequate considering their high levels of biodiversity and vulnerability. We hope to encourage readers to address current major challenges, such as how to manage grasslands for the benefit of diverse taxa, to ensure that conservation initiatives concentrate on sites where there is good potential for success and for the generation of realistic and viable conservation strategies.

  15. Classification of Grassland Successional Stages Using Airborne Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Thomas Möckel

    2014-08-01

    Full Text Available Plant communities differ in their species composition, and, thus, also in their functional trait composition, at different stages in the succession from arable fields to grazed grassland. We examine whether aerial hyperspectral (414–2501 nm remote sensing can be used to discriminate between grazed vegetation belonging to different grassland successional stages. Vascular plant species were recorded in 104.1 m2 plots on the island of Öland (Sweden and the functional properties of the plant species recorded in the plots were characterized in terms of the ground-cover of grasses, specific leaf area and Ellenberg indicator values. Plots were assigned to three different grassland age-classes, representing 5–15, 16–50 and >50 years of grazing management. Partial least squares discriminant analysis models were used to compare classifications based on aerial hyperspectral data with the age-class classification. The remote sensing data successfully classified the plots into age-classes: the overall classification accuracy was higher for a model based on a pre-selected set of wavebands (85%, Kappa statistic value = 0.77 than one using the full set of wavebands (77%, Kappa statistic value = 0.65. Our results show that nutrient availability and grass cover differences between grassland age-classes are detectable by spectral imaging. These techniques may potentially be used for mapping the spatial distribution of grassland habitats at different successional stages.

  16. Grassland ecology and population growth: striking a balance.

    Science.gov (United States)

    Hou, D; Duan, C; Zhang, D

    2000-06-01

    Degradation of forest and grasslands in western China attributes to the soil erosion and desertification in the country. Researchers have established that the primary reason for the degradation of grasslands is overgrazing, which in turn is caused by a number of factors, including over-population and over-reliance on animal husbandry. In addition, the existing administrative system has also proved ineffective in ensuring sustainable development. On contrary, many local governments even encourage exploitative development of grassland; thus, localities opened up grassland for growing crops in an effort to increase income. According to estimates, degraded grassland accounts for more than one-third of utilizable acreage and another one-third suffers from a profusion of rats and pests. To redress the situation, central government should implement strategies in achieving sustainable development, such as providing banking and tax incentives for the development of the secondary and tertiary industries, and supporting education and training of youths from herding areas. Moreover, government should increase spending on infrastructural construction and ecological preservation. Finally, the family planning program needs to be enforced to control population growth and improve the quality of peoples¿ lives.

  17. Organochlorine pollutants and stable isotopes in resident and migrant passerine birds from northwest Michoacán, Mexico.

    Science.gov (United States)

    Mora, Miguel A

    2008-10-01

    Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes delta(15)N, delta(13)C, and deltaD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001-2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes delta(15)N, delta(13)C, and deltaD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p'-DDE (100%), p,p'-DDT (57%), and total PCBs (100%). p,p'-DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues >10 microg/g wet weight in carcass. There were no significant differences in delta(13)C and delta(15)N values among species, between seasons, or between migrant and resident birds. However, deltaD values were clearly different between species and helped differentiate migrant from resident birds. deltaD values also were negatively and significantly correlated

  18. The pollination ecology of an assemblage of grassland asclepiads in South Africa.

    Science.gov (United States)

    Ollerton, Jeff; Johnson, Steven D; Cranmer, Louise; Kellie, Sam

    2003-12-01

    The KwaZulu-Natal region of South Africa hosts a large diversity of asclepiads (Apocynaceae: Asclepiadoideae), many of which are endemic to the area. The asclepiads are of particular interest because of their characteristically highly evolved floral morphology. During 3 months of fieldwork (November 2000 to January 2001) the flower visitors and pollinators to an assemblage of nine asclepiads at an upland grassland site were studied. These observations were augmented by laboratory studies of flower morphology (including scanning electron microscopy) and flower colour (using a spectrometer). Two of the specialized pollination systems that were documented are new to the asclepiads: fruit chafer pollination and pompilid wasp pollination. The latter is almost unique in the angiosperms. Taxa possessing these specific pollination systems cluster together in multidimensional phenotype space, suggesting that there has been convergent evolution in response to similar selection to attract identical pollinators. Pollination niche breadth varied from the very specialized species, with only one pollinator, to the more generalized, with up to ten pollinators. Pollinator sharing by the specialized taxa does not appear to have resulted in niche differentiation in terms of the temporal or spatial dimensions, or with regards to placement of pollinaria. Nestedness analysis of the data set showed that there was predictability and structure to the pattern of plant-pollinator interactions, with generalist insects visiting specialized plants and vice versa. The research has shown that there is still much to be learned about plant-pollinator interactions in areas of high plant diversity such as South Africa.

  19. Prescribed burning to affect a state transition in a shrub-encroached desert grassland

    Science.gov (United States)

    Prescribed burning is a commonly advocated and historical practice for control of woody species encroachment into grasslands on all continents. However, desert grasslands of the southwestern United States often lack needed herbaceous fuel loads for effective prescriptions, dominant perennial gramin...

  20. Fire as a control agent of demographic structure and plant performance of a rare Mediterranean endemic geophyte.

    Science.gov (United States)

    Diadema, Katia; Médail, Frédéric; Bretagnolle, François

    2007-09-01

    We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities and plant performance for a rare endemic geophyte, Acis nicaeensis (Alliaceae), in Mediterranean xerophytic grasslands of the 'Alpes-Maritimes' French 'département', through sampling plots in unburned and burned treatments. Fire increases density of flowering individuals and seedling emergence, as well as clump densities and number of individuals per clump, per limiting vegetation height and cover, and increasing bare soil cover. In contrast, fire has no effect on reproductive success. Nevertheless, two growing seasons after fire, all parameters of demographic stages and plant performance do not significantly differ between the two treatments. Small-scale fire is beneficial for the regeneration of this threatened geophyte at a short-time scale. In this context, a conservation planning with small and controlled fires could maintain the regeneration window for populations of rare Mediterranean geophytes.

  1. Carbon fluxes from an urban tropical grassland

    International Nuclear Information System (INIS)

    Ng, B.J.L.; Hutyra, L.R.; Nguyen, H.; Cobb, A.R.; Kai, F.M.; Harvey, C.; Gandois, L.

    2015-01-01

    Turfgrass covers a large fraction of the urbanized landscape, but the carbon exchange of urban lawns is poorly understood. We used eddy covariance and flux chambers in a grassland field manipulative experiment to quantify the carbon mass balance in a Singapore tropical turfgrass. We also assessed how management and variations in environmental factors influenced CO 2 respiration. Standing aboveground turfgrass biomass was 80 gC m −2 , with a mean ecosystem respiration of 7.9 ± 1.1 μmol m −2  s −1 . The contribution of autotrophic respiration was 49–76% of total ecosystem respiration. Both chamber and eddy covariance measurements suggest the system was in approximate carbon balance. While we did not observe a significant relationship between the respiration rates and soil temperature or moisture, daytime fluxes increased during the rainy interval, indicating strong overall moisture sensitivity. Turfgrass biomass is small, but given its abundance across the urban landscape, it significantly influences diurnal CO 2 concentrations. - Highlights: • We measured urban turfgrass CO 2 respiration rates and soil characteristics. • Mean observed ecosystem respiration was 7.9 ± 1.1 μmol m −2  s −1 . • Soil temperature and moisture were largely insignificant drivers of observed flux. - We found a Singapore urban turfgrass to be approximately carbon neutral, with a mean ecosystem respiration of 7.9 ± 1.1 μmol m −2  s −1

  2. Assessing the Effects of Grassland Management on Forage Production and Environmental Quality to Identify Paths to Ecological Intensification in Mountain Grasslands.

    Science.gov (United States)

    Loucougaray, Grégory; Dobremez, Laurent; Gos, Pierre; Pauthenet, Yves; Nettier, Baptiste; Lavorel, Sandra

    2015-11-01

    Ecological intensification in grasslands can be regarded as a process for increasing forage production while maintaining high levels of ecosystem functions and biodiversity. In the mountain Vercors massif, where dairy cattle farming is the main component of agriculture, how to achieve forage autonomy at farm level while sustaining environmental quality for tourism and local dairy products has recently stimulated local debate. As specific management is one of the main drivers of ecosystem functioning, we assessed the response of forage production and environmental quality at grassland scale across a wide range of management practices. We aimed to determine which components of management can be harnessed to better match forage production and environmental quality. We sampled the vegetation of 51 grasslands stratified across 13 grassland types. We assessed each grassland for agronomic and environmental properties, measuring forage production, forage quality, and indices based on the abundance of particular plant species such as timing flexibility, apiarian potential, and aromatic plants. Our results revealed an expected trade-off between forage production and environmental quality, notably by stressing the contrasts between sown and permanent grasslands. However, strong within-type variability in both production and environmental quality as well as in flexibility of timing of use suggests possible ways to improve this trade-off at grassland and farm scales. As achieving forage autonomy relies on increasing both forage production and grassland resilience, our results highlight the critical role of the ratio between sown and permanent grasslands as a major path for ecological intensification in mountain grasslands.

  3. Modeling effects of conservation grassland losses on amphibian habitat

    Science.gov (United States)

    Mushet, David M.; Neau, Jordan L.; Euliss, Ned H.

    2014-01-01

    Amphibians provide many ecosystem services valued by society. However, populations have declined globally with most declines linked to habitat change. Wetlands and surrounding terrestrial grasslands form habitat for amphibians in the North American Prairie Pothole Region (PPR). Wetland drainage and grassland conversion have destroyed or degraded much amphibian habitat in the PPR. However, conservation grasslands can provide alternate habitat. In the United States, the Conservation Reserve Program (CRP) is the largest program maintaining grasslands on agricultural lands. We used an ecosystem services model (InVEST) parameterized for the PPR to quantify amphibian habitat over a six-year period (2007–2012). We then quantified changes in availability of amphibian habitat under various land-cover scenarios representing incremental losses (10%, 25%, 50%, 75%, and 100%) of CRP grasslands from 2012 levels. The area of optimal amphibian habitat in the four PPR ecoregions modeled (i.e., Northern Glaciated Plains, Northwestern Glaciated Plains, Lake Agassiz Plain, Des Moines Lobe) declined by approximately 22%, from 3.8 million ha in 2007 to 2.9 million ha in 2012. These losses were driven by the conversion of CRP grasslands to croplands, primarily for corn and soybean production. Our modeling identified an additional 0.8 million ha (26%) of optimal amphibian habitat that would be lost if remaining CRP lands are returned to crop production. An economic climate favoring commodity production over conservation has resulted in substantial losses of amphibian habitat across the PPR that will likely continue into the future. Other regions of the world face similar challenges to maintaining amphibian habitats.

  4. Tools for Management for Grassland Ecosystem Sustainability: Thinking "Outside the Box"

    Science.gov (United States)

    Gerald J. Gottfried

    2004-01-01

    Grassland ecosystem management is dynamic and has adapted to the development of new tools and ideas. Our ancestors were indirectly managing grasslands when they learned to move livestock to take advantage of better water and greener forage. One could argue that even their hunting of grassland wildlife, especially the use of fire to drive animals to waiting hunters, had...

  5. Resilience and stability of the grasslands of the Transkei | B | African ...

    African Journals Online (AJOL)

    In spite of very high stocking rates the grasslands of Transkei still have in many areas a high cover and many climax species. The concepts of resilience and stability are used in an attempt to explain dynamics of the grasslands. Keywords: resiliences|stabilities|grasslands|Transkei|stocking rates|basal covers|grass ...

  6. Evapotranspiration and soil moisture dynamics in a temperate grassland ecosystem in Inner Mongolia China

    Science.gov (United States)

    L. Hao; Ge Sun; Yongqiang Liu; G. S. Zhou; J. H.   Wan;  L. B. Zhang; J. L. Niu; Y. H. Sang;  J. J He

    2015-01-01

    Precipitation, evapotranspiration (ET), and soil moisture are the key controls for the productivity and functioning of temperate grassland ecosystems in Inner Mongolia, northern China. Quantifying the soil moisture dynamics and water balances in the grasslands is essential to sustainable grassland management under global climate change. We...

  7. Voluntary intake and in vivo digestibility of forages from semi-natural grasslands in dairy cows

    NARCIS (Netherlands)

    Bruinenberg, M.H.; Valk, H.; Struik, P.C.

    2003-01-01

    To study in vivo digestibility of forages from semi-natural grasslands two experiments were carried out. In the first experiment lactating dairy cows were offered three different silage-based diets. Silage originated from intensively managed grassland (IM), extensively managed species-poor grassland

  8. Forest and grassland carbon in North America: A short course for land managers

    Science.gov (United States)

    Chris Swanston; Michael J. Furniss; Kristen Schmitt; Jeffrey Guntle; Maria Janowiak; Sarah Hines

    2012-01-01

    This multimedia short-course presents a range of information on the science, management and policy of forest and grassland carbon. Forests and grasslands worldwide play a critical role in storing carbon and sequestering greenhouse gases from the atmosphere. The U.S. Forest Service, which manages 193 million acres of forests and grasslands, emphasizes the need for...

  9. Histopathological survey of protozoa, helminths and acarids of imported and local psittacine and passerine birds in Japan.

    Science.gov (United States)

    Tsai, S S; Hirai, K; Itakura, C

    1992-12-01

    A total of 534 psittacine and passerine birds consisting of 241 imported and 293 local birds were examined histologically. As a result, the following parasites were found: Giardia (86 cases), Knemido-coptes (26 cases), coccidia (10 cases), Ascaridia (6 cases), Cryptosporidium (5 cases), Sarcocystis (5 cases), tapeworm (4 cases), microfilaria (2 cases), Hexamita (1 case), and Spiroptera (1 case). High incidences of giardiasis and knemido-coptic infestation were detected in the local birds, but rarely in the imported birds. Giardial trophozoites were observed mainly in the duodenum of budgerigars (Melopsittacus undulatus). Knemidocoptic mites burrowed into the epidermis producing proliferative dermatitis in 25 budgerigars and 1 African Grey Parrot (Psittacus erithacus erithacus). This ectoparasite often infested the skin around the cloaca. Coccidiosis was seen only in the small intestines of the finch (Poephila gouldiae gouldiae), African Grey Parrot, Rainbow lory (Trichoglossus haematodus), Indian Ring-necked parakeet (Psittacula krameri manillensis) and peach-faced lovebird (Agapornis roseicollis). Two parrots (Amazona aestiva aestiva and Psittacus erithacus erithacus) and two budgerigars had intestinal cryptosporidiosis. Conjunctivitis associated with cryptosporidial infection was seen in a lovebird. Sarcocystis cysts containing crescent-shaped bradyzoites were found not only in the thigh and breast but also in the heart and cloacal muscles. Other organisms such as Ascaridia, tapeworm, microfilaria, Hexamita, and Spiroptera were clinically less significant. However, infections such as Giardia and Cryptosporidim might have zoonotic implications.

  10. Large-scale geographical variation in eggshell metal and calcium content in a passerine bird (Ficedula hypoleuca).

    Science.gov (United States)

    Ruuskanen, Suvi; Laaksonen, Toni; Morales, Judith; Moreno, Juan; Mateo, Rafael; Belskii, Eugen; Bushuev, Andrey; Järvinen, Antero; Kerimov, Anvar; Krams, Indrikis; Morosinotto, Chiara; Mänd, Raivo; Orell, Markku; Qvarnström, Anna; Slate, Fred; Tilgar, Vallo; Visser, Marcel E; Winkel, Wolfgang; Zang, Herwig; Eeva, Tapio

    2014-03-01

    Birds have been used as bioindicators of pollution, such as toxic metals. Levels of pollutants in eggs are especially interesting, as developing birds are more sensitive to detrimental effects of pollutants than adults. Only very few studies have monitored intraspecific, large-scale variation in metal pollution across a species' breeding range. We studied large-scale geographic variation in metal levels in the eggs of a small passerine, the pied flycatcher (Ficedula hypoleuca), sampled from 15 populations across Europe. We measured 10 eggshell elements (As, Cd, Cr, Cu, Ni, Pb, Zn, Se, Sr, and Ca) and several shell characteristics (mass, thickness, porosity, and color). We found significant variation among populations in eggshell metal levels for all metals except copper. Eggshell lead, zinc, and chromium levels decreased from central Europe to the north, in line with the gradient in pollution levels over Europe, thus suggesting that eggshell can be used as an indicator of pollution levels. Eggshell lead levels were also correlated with soil lead levels and pH. Most of the metals were not correlated with eggshell characteristics, with the exception of shell mass, or with breeding success, which may suggest that birds can cope well with the current background exposure levels across Europe.

  11. Nest predation risk and growth strategies of passerine species: grow fast or develop traits to escape risk?

    Science.gov (United States)

    Cheng, Yi-Ru; Martin, Thomas E.

    2012-01-01

    Different body components are thought to trade off in their growth and development rates, but the causes for relative prioritization of any trait remains a critical question. Offspring of species at higher risk of predation might prioritize development of locomotor traits that facilitate escaping risky environments over growth of mass. We tested this possibility in 12 altricial passerine species that differed in their risk of nest predation. We found that rates of growth and development of mass, wings, and endothermy increased with nest predation risk across species. In particular, species with higher nest predation risk exhibited relatively faster growth of wings than of mass, fledged with relatively larger wing sizes and smaller mass, and developed endothermy earlier at relatively smaller mass. This differential development can facilitate both escape from predators and survival outside of the nest environment. Tarsus growth was not differentially prioritized with respect to nest predation risk, and instead all species achieved adult tarsus size by age of fledging. We also tested whether different foraging modes (aerial, arboreal, and ground foragers) might explain the variation of differential growth of locomotor modules, but we found that little residual variation was explained. Our results suggest that differences in nest predation risk among species are associated with relative prioritization of body components to facilitate escape from the risky nest environment.

  12. Effects of haying on breeding birds in CRP grasslands

    Science.gov (United States)

    Igl, Lawrence D.; Johnson, Douglas H.

    2016-01-01

    The Conservation Reserve Program (CRP) is a voluntary program that is available to agricultural producers to help protect environmentally sensitive or highly erodible land. Management disturbances of CRP grasslands generally are not allowed unless authorized to provide relief to livestock producers during severe drought or a similar natural disaster (i.e., emergency haying and grazing) or to improve the quality and performance of the CRP cover (i.e., managed haying and grazing). Although CRP grasslands may not be hayed or grazed during the primary bird-nesting season, these disturbances may have short-term (1 yr after disturbance) and long-term (≥2 yr after disturbance) effects on grassland bird populations. We assessed the effects of haying on 20 grassland bird species in 483 CRP grasslands in 9 counties of 4 states in the northern Great Plains, USA between 1993 and 2008. We compared breeding bird densities (as determined by total-area counts) in idle and hayed fields to evaluate changes 1, 2, 3, and 4 years after haying. Haying of CRP grasslands had either positive or negative effects on grassland birds, depending on the species, the county, and the number of years after the initial disturbance. Some species (e.g., horned lark [Eremophila alpestris], bobolink [Dolichonyx oryzivorus]) responded positively after haying, and others (e.g., song sparrow [Melospiza melodia]) responded negatively. The responses of some species changed direction as the fields recovered from haying. For example, densities for common yellowthroat (Geothlypis trichas), sedge wren (Cistothorus platensis), and clay-colored sparrow (Spizella pallida) declined the first year after haying but increased in the subsequent 3 years. Ten species showed treatment × county interactions, indicating that the effects of haying varied geographically. This long-term evaluation on the effects of haying on breeding birds provides important information on the strength and direction of changes in

  13. Optimising Regionalisation Techniques: Identifying Centres of Endemism in the Extraordinarily Endemic-Rich Cape Floristic Region

    Science.gov (United States)

    Bradshaw, Peter L.; Colville, Jonathan F.; Linder, H. Peter

    2015-01-01

    We used a very large dataset (>40% of all species) from the endemic-rich Cape Floristic Region (CFR) to explore the impact of different weighting techniques, coefficients to calculate similarity among the cells, and clustering approaches on biogeographical regionalisation. The results were used to revise the biogeographical subdivision of the CFR. We show that weighted data (down-weighting widespread species), similarity calculated using Kulczinsky’s second measure, and clustering using UPGMA resulted in the optimal classification. This maximized the number of endemic species, the number of centres recognized, and operational geographic units assigned to centres of endemism (CoEs). We developed a dendrogram branch order cut-off (BOC) method to locate the optimal cut-off points on the dendrogram to define candidate clusters. Kulczinsky’s second measure dendrograms were combined using consensus, identifying areas of conflict which could be due to biotic element overlap or transitional areas. Post-clustering GIS manipulation substantially enhanced the endemic composition and geographic size of candidate CoEs. Although there was broad spatial congruence with previous phytogeographic studies, our techniques allowed for the recovery of additional phytogeographic detail not previously described for the CFR. PMID:26147438

  14. Taenia solium in Europe: Still endemic?

    Science.gov (United States)

    Devleesschauwer, Brecht; Allepuz, Alberto; Dermauw, Veronique; Johansen, Maria V; Laranjo-González, Minerva; Smit, G Suzanne A; Sotiraki, Smaragda; Trevisan, Chiara; Wardrop, Nicola A; Dorny, Pierre; Gabriël, Sarah

    2017-01-01

    The pork tapeworm, Taenia solium, causes an important economic and health burden, mainly in rural or marginalized communities of sub-Saharan Africa, Asia, and Latin-America. Although improved pig rearing conditions seem to have eliminated the parasite in most Western European countries, little is known about the true endemicity status of T. solium throughout Europe. Three recent reviews indicate that autochthonous human T. solium taeniasis/cysticercosis may be possible in Europe, but that current peer-reviewed literature is biased towards Western Europe. Officially reported data on porcine cysticercosis are highly insufficient. Favourable conditions for local T. solium transmission still exist in eastern parts of Europe, although the ongoing integration of the European Union is speeding up modernisation and intensification of the pig sector. Further evidence is urgently needed to fill the gaps on the European T. solium endemicity map. We urge to make human cysticercosis notifiable and to improve the reporting of porcine cysticercosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Diversity and endemism of Peruvian mammals

    Directory of Open Access Journals (Sweden)

    Víctor Pacheco

    2011-07-01

    Full Text Available We present an annotated list for all land, aquatic and marine mammals known to occur in Peru and their distribution by ecoregions. We also present species conservation status according to international organizations and the legal conservation status in Peru. At present, we record 508 species, in 13 orders, 50 families, and 218 genera, making Peru the third most diverse country with regards to mammals in the New World, after Brazil and Mexico, and the fifth most diverse country for mammals in the World. This diversity includes 40 didelphimorphs, 2 paucituberculates, 1 manatee, 6 cingulates, 7 pilosa, 39 primates, 162 rodents, 1 rabbit, 2 soricomorphs, 165 bats, 34 carnivores, 2 perissodactyls, and 47 cetartiodactyls. Bats and rodents (327 species represent almost two thirds of total diversity (64% for Peru. Five genera and 65 species (12.8% are endemics to Peru, with the majority of these being rodents (45 species, 69,2%. Most of the endemic species are restricted to the Yungas of the eastern slope of the Andes (39 species, 60% followed by Selva Baja (14 species, 21.5%. The taxonomic status of some species is commented on, when those depart from accepted taxonomy. The marsupial Marmosa phaea; the rodents Melanomys caliginosus, M. robustulus, and Echinoprocta rufescens; the shrew Cryptotis equatoris; the bats Anoura fistulata, Phyllostomus latifolius, Artibeus ravus, Cynomops greenhalli, Eumops maurus, and Rhogeessa velilla; and the carnivore Nasuella olivacea are first records of species occurrence in Peru. Finally, we also include a list of 15 non-native species.

  16. Functional characterization of spectral tuning mechanisms in the great bowerbird short-wavelength sensitive visual pigment (SWS1), and the origins of UV/violet vision in passerines and parrots.

    Science.gov (United States)

    van Hazel, Ilke; Sabouhanian, Amir; Day, Lainy; Endler, John A; Chang, Belinda S W

    2013-11-13

    One of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures. The great bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a λmax of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted λmax into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor. Our mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type

  17. DYNAMICS OF CARBON SEQUESTRATION IN ABANDONED GRASSLANDS OF NORTHEASTERN MEXICO

    Directory of Open Access Journals (Sweden)

    José Israel Yerena Yamallel

    2014-04-01

    Full Text Available Livestock activities due to the improper handling of the load capacity, suffer from low productivity in their grasslands, which are abandoned giving rise to the appearance of species considered invasive and undesirable for producers, without knowing the qualities of these as mitigating of climate change. The objective of the present study was to estimate the carbon content in tamaulipan thornscrub and three abandoned grasslands with a time of abandonment of 10, 20 and 30 years. For the estimation of the carbon content was used a systematic sampling design, in each area were established four sampling sites of 1,600 m2. The primary scrub is the system that resulted in the largest value of carbon content of 14.25 Mg ha-1, followed by the grasslands of 30, 20 and 10 years with 8.03, 7.33 and 4.13 Mg ha-1 respectively. It was concluded that recovering the initial state of the primary scrub take many years, as can be seen in the grasslands system 30 years reaching only 56% of what it had in reserves of primary scrub.

  18. Quantitative ecological relationships in the alpine grassland of ...

    African Journals Online (AJOL)

    A survey, based on 56 000 points at 102 sampling sites in the Tsehlanyane valley of the Oxbow (Madibamatso) Dam catchment in the alpine grassland of Lesotho, indicates that the area is generally in good condition. Physiographic and floristic criteria were measured and the association between pairs of criteria statistically ...

  19. Crude protein changes on grassland along a degradation gradient ...

    African Journals Online (AJOL)

    Evapotranspiration was determined by quantifying the soil-water balance equation with the aid of runoff plots and soil-water content measurements. Crude protein ... The study shows that it is important to keep grassland in optimal condition to utilize limited soil water for sustainable plant and therefore animal production.

  20. Intensification of grassland and forage use: driving forces and constraints

    NARCIS (Netherlands)

    Oenema, O.; Klein, de C.; Alfaro, M.

    2014-01-01

    The increasing demand for safe and nutritional dairy and beef products in a globalising world, together with the needs to increase resource use efficiency and to protect biodiversity, provide strong incentives for intensification of grassland and forage use. This paper addresses the question: 'Does

  1. Achieving grassland production and quality that matches animal needs

    NARCIS (Netherlands)

    Pol, van den A.; Busqué, Juan; Golinski, P.; Noorkõiv, Katrin; O'Donovan, Michael; Peratoner, Giovanni; Reheul, D.

    2016-01-01

    Permanent grasslands are exploited by grazing animals or as meadows depending on different
    constraints. Grazing is the most common use in large parts of Europe, especially in the northwest of
    Europe. However, certain areas are less suitable for grazing. In the Alps e.g. meadows are the

  2. Achieving grassland production and quality that matching animal needs

    NARCIS (Netherlands)

    Pol, van den A.; Busqué, Juan; Golinski, P.; Noorkõiv, Katrin; O'Donovan, Michael; Peratoner, Giovanni; Reheul, D.

    2016-01-01

    Permanent grasslands are exploited by grazing animals or as meadows depending on different constraints. Grazing is the most common use in large parts of Europe, especially in the northwest of Europe. However, certain areas are less suitable for grazing. In the Alps e.g. meadows are the most relevant

  3. Avian diversity in the Naliya Grassland, Abdasa Taluka, Kachchh, India

    Directory of Open Access Journals (Sweden)

    Sandeep B Munjpara

    2012-03-01

    Full Text Available Naliya Grassland is one of the significant grasslands of Gujarat. In this study the importance of the Naliya Grassland has been explored with special reference to avian diversity. Field work for the study was carried out throughout the year of 2007 on a monthly basis covering three distinct seasons to explore avian diversity. A total of 177 species belonging to 54 families were recorded wherein most species belonged to the family Accipitridae (20 species followed by Alaudidae (11 species. Of the total families, five were represented by more than seven species, 18 families by 3-7 species and 31 families by one or two species respectively. Among the species observed, 16 species ware globally threatened (three Critically Endangered, four Endangered and nine Near Threatened. Most of the species were chiefly terrestrial (68.2%, about 23.9% species were freshwater dependant and 7.9% utilized mixed habitats. Maximum species richness was recorded in the monsoons and minimum in summer. Constant turnover and fluctuation in species richness occurred because of seasonal immigration and emigration. Maximum emigration took place during February and March and maximum immigration occurred during June and July. Many water dependant birds attracted to the flooded grassland during the monsoons explained the high species richness during this season. In winter, the area was inhabited by resident species as well as many migratory species.

  4. Evaluation of SPOT imagery for the estimation of grassland biomass

    Science.gov (United States)

    Dusseux, P.; Hubert-Moy, L.; Corpetti, T.; Vertès, F.

    2015-06-01

    In many regions, a decrease in grasslands and change in their management, which are associated with agricultural intensification, have been observed in the last half-century. Such changes in agricultural practices have caused negative environmental effects that include water pollution, soil degradation and biodiversity loss. Moreover, climate-driven changes in grassland productivity could have serious consequences for the profitability of agriculture. The aim of this study was to assess the ability of remotely sensed data with high spatial resolution to estimate grassland biomass in agricultural areas. A vegetation index, namely the Normalized Difference Vegetation Index (NDVI), and two biophysical variables, the Leaf Area Index (LAI) and the fraction of Vegetation Cover (fCOVER) were computed using five SPOT images acquired during the growing season. In parallel, ground-based information on grassland growth was collected to calculate biomass values. The analysis of the relationship between the variables derived from the remotely sensed data and the biomass observed in the field shows that LAI outperforms NDVI and fCOVER to estimate biomass (R2 values of 0.68 against 0.30 and 0.50, respectively). The squared Pearson correlation coefficient between observed and estimated biomass using LAI derived from SPOT images reached 0.73. Biomass maps generated from remotely sensed data were then used to estimate grass reserves at the farm scale in the perspective of operational monitoring and forecasting.

  5. Homogenization of the soil surface following fire in semiarid grasslands

    Science.gov (United States)

    Carleton S. White

    2011-01-01

    Semiarid grasslands accumulate soil beneath plant "islands" that are raised above bare interspaces. This fine-scale variation in microtopographic relief is plant-induced and is increased with shrub establishment. Research found that fire-induced water repellency enhanced local-scale soil erosion that reduced variation in microtopographic relief, suggesting...

  6. Relationship between soil chemical factors and grassland diversity

    NARCIS (Netherlands)

    Janssens, F; Peeters, A; Tallowin, JRB; Bakker, JP; Bekker, RM; Fillat, F; Oomes, MJM

    Many studies carried out during these last few years have focused on the factors influencing plant diversity in species-rich grasslands. This is due to the fact that these ecosystems, among the most diversified in temperate climates, are extremely threatened; in some areas, they have almost

  7. Transformation of a savanna grassland by drought and grazing | O ...

    African Journals Online (AJOL)

    The relative effects of drought and heavy grazing on the floristic composition, population size and and structure, and basal cover of an African savanna grassland were differentiated by comparing changes over eight years over eight years, which included a severe drought year, across a gradient of grazing history. Drought ...

  8. Controlling nitrous oxide emissions from grassland livestock production systems

    NARCIS (Netherlands)

    Oenema, O.; Gebauer, G.; Rodriguez, M.; Sapek, A.; Jarvis, S.C.; Corré, W.J.; Yamulki, S.

    1998-01-01

    There is growing awareness that grassland livestock production systems are major sources of nitrous oxide (N2O). Controlling these emissions requires a thorough understanding of all sources and controlling factors at the farm level. This paper examines the various controlling factors and proposes

  9. Effects of large herbivores on grassland arthropod diversity

    NARCIS (Netherlands)

    van Klink, R.; van der Plas, F.; van Noordwijk, C. G. E. (Toos); WallisDeVries, M. F.; Olff, H.

    Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141

  10. Potassium cycling and losses in grassland systems : a review

    NARCIS (Netherlands)

    Kayser, M; Isselstein, J

    Cycling of potassium in grassland systems has received relatively little attention in research and practice in recent years. Balanced nutrient systems require consideration of nutrients other than nitrogen (N). Potassium (K) is needed in large amounts and is closely related to N nutrition. In

  11. The effect of grassland management on enchytraeids (Oligochaeta) communities

    DEFF Research Database (Denmark)

    Maraldo, Kristine; Schmelz, Rüdiger; Christensen, Bent Tolstrup

    2012-01-01

    Enchytraeids (small white earthworms between 3 to 35 mm) are important regulators of nitrogen turnover in grasslands, as their activities accelerate the decomposition and nutrient recycling processes. In this study, the effect of management on species composition, abundance and biomass of the enc...... biomass and density of the grazed plots are due to compaction by grazing animals....

  12. Effect of burn area on invertebrate recolonization in grasslands in ...

    African Journals Online (AJOL)

    Our study examined the short-term response of grassland invertebrate communities to fire in the South African Drakensberg, in relation to distance from the edge of a burn. We aimed to establish which species survive fire and the dynamics of the post-fire recolonization process, and thereby contribute to establishing the ...

  13. Organic matter dynamics and N mineralization in grassland soils

    NARCIS (Netherlands)

    Hassink, J.

    1995-01-01


    The aims of this study are i) to improve our understanding of the interactions between soil texturelsoil structure, soil organic matter, soil biota and mineralization in grassland soils, ii) to develop a procedure that yields soil organic matter fractions that can be determined directly

  14. Vegetation diversity of salt-rich grasslands in Southeast Europe

    Czech Academy of Sciences Publication Activity Database

    Eliáš, P. Jr.; Sopotlieva, D.; Dítě, D.; Hájková, Petra; Apostolova, I.; Senko, D.; Melečková, Z.; Hájek, Michal

    2013-01-01

    Roč. 16, č. 3 (2013), s. 521-537 ISSN 1402-2001 R&D Projects: GA ČR GA206/09/0329 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : salt marshes * vegetation survey * grasslands Subject RIV: EF - Botanics Impact factor: 2.416, year: 2013

  15. Hydroclimatological Controls of Endemic and Non-endemic Cholera of the 20th Century

    Science.gov (United States)

    Jutla, A. S.; Whitcombe, E.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat for the developing countries. Since the causative agent, Vibrio cholerae, is autochthonous to aquatic environment, it is not possible to eradicate the agent of the disease. Hydroclimatology based prediction and prevention strategies can be implemented in disease susceptible regions for reducing incidence rates. However, the precise role of hydrological and climatological processes, which will further aid in development of suitable prediction models, in creating spatial and temporal environmental conditions favorable for disease outbreak has not been adequately quantified. Here, we show distinction between seasonality and occurrence of cholera in epidemic and non-endemic regions. Using historical cholera mortality data, from the late 1800s for 27 locations in the Indian subcontinent, we show that non-endemic regions are generally located close to regional river systems but away from the coasts and are characterized by single sporadic outbreak in a given year. Increase in air temperature during the low river flow season increases evaporation, leading to an optimal salinity and pH required for bacterial growth. Thereafter, monsoonal rainfall, leads to interactions of contaminated river waters via human activity resulting in cholera epidemics. Endemic regions are located close to coasts where cholera outbreak occurs twice (spring and fall) in a year. Spring outbreak is generally associated with intrusion of bacterial seawater to inland whereas the fall peak is correlated with widespread flooding and cross-contamination of water resources via increased precipitation. This may be one of the first studies to hydroclimatologically quantitatively the seasonality of cholera in both endemic and non-endemic regions. Our results prompt the need of region and cause-specific prediction models for cholera, employing appropriate environmental determinants.

  16. Accumulation of Dechlorane Plus flame retardant in terrestrial passerines from a nature reserve in South China: The influences of biological and chemical variables

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Ying [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jiang-Ping, E-mail: jpwu@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Tao, Lin [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Mo, Ling [Hainan Research Academy of Environmental Sciences, Haikou 571126 (China); Zheng, Xiao-Bo; Tang, Bin [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Luo, Xiao-Jun; Mai, Bi-Xian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2015-05-01

    Although a number of studies have addressed the bioaccumulation of Dechlorane Plus (DP) flame retardant in wildlife, few data are available on terrestrial organisms. This study examined the presence of DP isomers in the muscle tissue of seven terrestrial resident passerine species, i.e., the great tit (Parus major), the oriental magpie-robin (Copsychus saularis), the red-whiskered bulbul (Pycnonotus jocosus), the light-vented bulbul (Pycnonotus sinensis), the streak-breasted scimitar babbler (Pomatorhinus ruficollis), the long-tailed shrike (Lanius schach), and the orange-headed thrush (Zoothera citrina), from a national nature reserve located in South China. The ∑DP (sum of syn-DP and anti-DP) concentrations ranged from 1.2 to 104 ng/g lipid weight, with significantly higher levels in insectivorous birds than in omnivorous birds. The overall exposure to DP isomers of the current passerines may be attributed to the intensive release of this pollutant from electronic waste recycling sites and industrial zones in the vicinity of the nature reserve. Species-specific DP isomeric profiles were also found, with significantly greater f{sub anti} values (the isomer fractions of anti-DP) in the red-whiskered bulbul and the oriental magpie-robin. Additionally, the f{sub anti} values were significantly negatively correlated to ∑DP concentrations for the individual bird samples, suggesting the influence of DP concentrations on the isomeric profiles. - Highlights: • We investigated the occurrence of DP in seven species of terrestrial passerines. • Insectivorous birds accumulated higher ∑DP concentrations than omnivorous birds. • Inter-species differences in the f{sub anti} values were observed. • The f{sub anti} values were significantly correlated to DP concentrations.

  17. Accumulation of Dechlorane Plus flame retardant in terrestrial passerines from a nature reserve in South China: The influences of biological and chemical variables

    International Nuclear Information System (INIS)

    Peng, Ying; Wu, Jiang-Ping; Tao, Lin; Mo, Ling; Zheng, Xiao-Bo; Tang, Bin; Luo, Xiao-Jun; Mai, Bi-Xian

    2015-01-01

    Although a number of studies have addressed the bioaccumulation of Dechlorane Plus (DP) flame retardant in wildlife, few data are available on terrestrial organisms. This study examined the presence of DP isomers in the muscle tissue of seven terrestrial resident passerine species, i.e., the great tit (Parus major), the oriental magpie-robin (Copsychus saularis), the red-whiskered bulbul (Pycnonotus jocosus), the light-vented bulbul (Pycnonotus sinensis), the streak-breasted scimitar babbler (Pomatorhinus ruficollis), the long-tailed shrike (Lanius schach), and the orange-headed thrush (Zoothera citrina), from a national nature reserve located in South China. The ∑DP (sum of syn-DP and anti-DP) concentrations ranged from 1.2 to 104 ng/g lipid weight, with significantly higher levels in insectivorous birds than in omnivorous birds. The overall exposure to DP isomers of the current passerines may be attributed to the intensive release of this pollutant from electronic waste recycling sites and industrial zones in the vicinity of the nature reserve. Species-specific DP isomeric profiles were also found, with significantly greater f anti values (the isomer fractions of anti-DP) in the red-whiskered bulbul and the oriental magpie-robin. Additionally, the f anti values were significantly negatively correlated to ∑DP concentrations for the individual bird samples, suggesting the influence of DP concentrations on the isomeric profiles. - Highlights: • We investigated the occurrence of DP in seven species of terrestrial passerines. • Insectivorous birds accumulated higher ∑DP concentrations than omnivorous birds. • Inter-species differences in the f anti values were observed. • The f anti values were significantly correlated to DP concentrations

  18. Comparison of immune responses to a killed bivalent whole cell oral cholera vaccine between endemic and less endemic settings.

    Science.gov (United States)

    Desai, Sachin N; Akalu, Zenebe; Teferi, Mekonnen; Manna, Byomkesh; Teshome, Samuel; Park, Ju Yeon; Yang, Jae Seung; Kim, Deok Ryun; Kanungo, Suman; Digilio, Laura

    2016-02-01

    Studies on safety, immunogenicity and efficacy of the killed, bivalent whole cell oral cholera vaccine (Shanchol) have been conducted in historically endemic settings of Asia. Recent cholera vaccination campaigns in Haiti and Guinea have also demonstrated favourable immunogenicity and effectiveness in nonendemic outbreak settings. We performed a secondary analysis, comparing immune responses of Shanchol from two randomised controlled trials performed in an endemic and a less endemic area (Addis Ababa) during a nonoutbreak setting. While Shanchol may offer some degree of immediate protection in primed populations living in cholera endemic areas, as well as being highly immunogenic in less endemic settings, understanding the characteristics of immune responses in each of these areas is vital in determining ideal dosing strategies that offer the greatest public health impact to populations from areas with varying degrees of cholera endemicity. © 2015 John Wiley & Sons Ltd.

  19. Risk from cattle trampling to nests of an endangered passerine evaluated using artificial nest experiments and simulations

    Directory of Open Access Journals (Sweden)

    Brian W. Rolek

    2016-06-01

    Full Text Available Grasslands are often grazed by cattle and many grassland birds nest on the ground, potentially exposing nests to trampling. We tested for trampling risk introduced by cattle to nests of endangered Florida Grasshopper Sparrows (Ammodramus savannarum floridanus using experimentally paired grids of artificial nests (i.e., clay targets similar in size to nests of Florida Grasshopper Sparrows and counted the number of clay targets that were broken in paired grazed and ungrazed enclosures. Clay targets in grazed grids were trampled 3.9% more often than their respective ungrazed grids, and measurements of cattle presence or density were correlated with the number of broken clay targets, suggesting that excluding cattle during breeding is an important management recommendation for the Florida Grasshopper Sparrow. Trampling rates within grazed enclosures were spatially homogeneous with respect to cattle infrastructure such as supplemental feeding troughs and fences, and forests and stocking density were poor predictors of trampling rates when excluding ungrazed grids. We used population viability analysis to compare quasi-extinction rates, intrinsic growth rates, and median abundance in grazed and ungrazed Florida Grasshopper Sparrow aggregations to further understand the biological significance of management aimed at reducing trampling rates during the breeding season. Simulations indicated that trampling from grazing increased quasi-extinction rates by 41% while reducing intrinsic growth rates by 0.048, and reducing median abundance by an average of 214 singing males after 50 years. Management should avoid grazing enclosures occupied by Florida Grasshopper Sparrows during the nesting season to minimize trampling rates. Our methods that combine trampling experiments with population viability analysis provide a framework for testing effects from trampling on other grassland ground-nesting birds, and can directly inform conservation and management of the

  20. Density and fledging success of ground-nesting passerines in Conservation Reserve Program fields in the northeastern Great Plains

    Science.gov (United States)

    Koford, Rolf R.

    1999-01-01

    The Conservation Reserve Program, initiated in 1985, was designed primarily to reduce soil erosion and crop surpluses. A secondary benefit was the provision of habitat for wildlife. Grassland bird populations, many of which declined in the decades prior to the Conservation Reserve Program, may have benefited from the Conservation Reserve Program if reproduction in this newly available habitat has been at least as high as it would have been in the absence of the Conservation Reserve Program. On study areas in North Dakota and Minnesota, I examined breeding densities and fledging success of grassland birds in Conservation Reserve Program fields and in an alternative habitat of similar structure, idle grassland fields on federal Waterfowl Production Areas. Fields were 10 to 25 hectares in size. The avifaunas of these two habitats were similar, although brush-dependent species were more abundant on Waterfowl Protection Areas. The common species in these habitats included ones whose continental populations have declined, such as Grasshopper Sparrow (Ammodramus savannarum), Savannah Sparrow (Passerculus sandwichensis), and Bobolink (Dolichonyx oryzivorus). These ground-nesting species were pooled with other ground nesters in an analysis of fledging success, which revealed no significant differences between habitats, between states, or among years (1991-1993). Predation was the primary cause of nest failure. I concluded that Conservation Reserve Program fields in this region were suitable breeding habitat for several species whose populations had declined prior to the Conservation Reserve Program era. This habitat appeared to be as secure for nests of ground-nesting birds as another suitable habitat in North Dakota and Minnesota.

  1. Managed grassland alters soil N dynamics and N2O emissions in temperate steppe.

    Science.gov (United States)

    Xu, Lijun; Xu, Xingliang; Tang, Xuejuan; Xin, Xiaoping; Ye, Liming; Yang, Guixia; Tang, Huajun; Lv, Shijie; Xu, Dawei; Zhang, Zhao

    2018-04-01

    Reclamation of degraded grasslands as managed grasslands has been increasingly accelerated in recent years in China. Land use change affects soil nitrogen (N) dynamics and nitrous oxide (N 2 O) emissions. However, it remains unclear how large-scale grassland reclamation will impact the grassland ecosystem as a whole. Here, we investigated the effects of the conversion from native to managed grasslands on soil N dynamics and N2O emissions by field experiments in Hulunber in northern China. Soil (0-10cm), nitrate (NO 3 - ), ammonium (NH 4 + ), and microbial N were measured in plots in a temperate steppe (Leymus chinensis grassland) and two managed grasslands (Medicago sativa and Bromus inermis grasslands) in 2011 and 2012. The results showed conversion of L. chinensis grassland to M. sativa or B. inermis grasslands decreased concentrations of NO 3 - -N, but did not change NH 4 + -N. Soil microbial N was slightly decreased by the conversion of L. chinensis grassland to M. sativa, but increased by the conversion to B. inermis. The conversion of L. chinensis grassland to M. sativa (i.e., a legume grass) increased N 2 O emissions by 26.2%, while the conversion to the B. inermis (i.e., a non-legume grass) reduced N 2 O emissions by 33.1%. The conversion from native to managed grasslands caused large created variations in soil NO 3 - -N and NH 4 + -N concentrations. Net N mineralization rates did not change significantly in growing season or vegetation type, but to net nitrification rate. These results provide evidence on how reclamation may impact the grassland ecosystem in terms of N dynamics and N 2 O emissions. Copyright © 2017. Published by Elsevier B.V.

  2. Effects of temperature and precipitation on grassland bird nesting success as mediated by patch size.

    Science.gov (United States)

    Zuckerberg, Benjamin; Ribic, Christine A; McCauley, Lisa A

    2018-02-06

    Grassland birds are declining faster than any other bird guild across North America. Shrinking ranges and population declines are attributed to widespread habitat loss and increasingly fragmented landscapes of agriculture and other land uses that are misaligned with grassland bird conservation. Concurrent with habitat loss and degradation, temperate grasslands have been disproportionally affected by climate change relative to most other terrestrial biomes. Distributions of grassland birds often correlate with gradients in climate, but few researchers have explored the consequences of weather on the demography of grassland birds inhabiting a range of grassland fragments. To do so, we modeled the effects of temperature and precipitation on nesting success rates of 12 grassland bird species inhabiting a range of grassland patches across North America (21,000 nests from 81 individual studies). Higher amounts of precipitation in the preceding year were associated with higher nesting success, but wetter conditions during the active breeding season reduced nesting success. Extremely cold or hot conditions during the early breeding season were associated with lower rates of nesting success. The direct and indirect influence of temperature and precipitation on nesting success was moderated by grassland patch size. The positive effects of precipitation in the preceding year on nesting success were strongest in relatively small grassland patches and had little effect in large patches. Conversely, warm temperatures reduced nesting success in small grassland patches but increased nesting success in large patches. Mechanisms underlying these differences may be patch-size-induced variation in microclimates and predator activity. Although the exact cause is unclear, large grassland patches, the most common metric of grassland conservation, appears to moderate the effects of weather on grassland-bird demography and could be an effective component of climate-change adaptation.

  3. Evolution of sexual dichromatism in relation to nesting habits in European passerines: a test of Wallace's hypothesis.

    Science.gov (United States)

    Soler, J J; Moreno, J

    2012-08-01

    Wallace proposed in 1868 that natural rather than sexual selection could explain the striking differences in avian plumage dichromatism. Thus, he predicted that nesting habits, through their association with nest predation, could drive changes in sexual dichromatism by enabling females in cavity nesters to become as conspicuous as males, whereas Darwin (1871, The Descent of Man and Selection in Relation to Sex, John Murray, London) argued that sexual selection was the sole explanation for dichromatism. Sexual dichromatism is currently used as indicating the strength of sexual selection, and therefore testing Wallace's claim with modern phylogentically controlled methodologies is of prime interest for comparing the roles of natural and sexual selection in affecting the evolution of avian coloration. Here, we have related information on nest attendance, sexual dichromatism and nesting habits (open and cavity nesting) to male and female plumage conspicuousness in European passerines. Nest incubation attendance does not explain male or female plumage conspicuousness but nest type does. Moreover, although females of monochromatic and cavity nesting species are more conspicuous than females of other species, males of monochromatic and open nesting species are those with more cryptic plumage. Finally, analyses of character evolution suggest that changes in nesting habits influence the probability of changes in both dichromatism and plumage conspicuousness of males but do not significantly affect those in females. These results strongly suggest a role of nesting habits in the evolution of plumage conspicuousness of males, and a role for sexual selection also in females, both factors affecting the evolution of sexual dichromatism. We discuss our findings in relation to the debate that Darwin and Wallace maintained more than one century ago on the importance of natural and sexual selection in driving the evolution of plumage conspicuousness and sexual dichromatism in birds

  4. Growth strategies of passerine birds are related to brood parasitism by the brown-headed cowbird (Molothrus ater).

    Science.gov (United States)

    Remes, Vladimír

    2006-08-01

    Sibling competition was proposed as an important selective agent in the evolution of growth and development. Brood parasitism by the brown-headed cowbird (Molothrus ater) intensifies sibling competition in the nests of its hosts by increasing host chick mortality and exposing them to a genetically unrelated nestmate. Intranest sibling competition for resources supplied by parents is size dependent. Thus, it should select for high development rates and short nestling periods, which would alleviate negative impacts of brood parasitic chicks on host young. I tested these predictions on 134 North American passerines by comparative analyses. After controlling for covariates and phylogeny, I showed that high parasitism rate was associated with higher nestling growth rate, lower mass at fledging, and shorter nestling periods. These effects were most pronounced in species in which sibling competition is most intense (i.e., weighing over about 30 g). When species were categorized as nonhosts versus old hosts (parasitized for thousands of years) versus new hosts (parasitized the last 100-200 years), there was a clear effect of this parasitism category on growth strategies. Nestling growth rate was the most evolutionarily flexible trait, followed by mass at fledging and nestling period duration. Adjustments during incubation (incubation period length, egg volume) were less pronounced and generally disappeared after controlling for phylogeny. I show that sibling competition caused by brood parasites can have strong effects on the evolution of host growth strategies and that the evolution of developmental traits can take place very rapidly. Human alteration of habitats causing spread of brood parasites to new areas thus cascades into affecting the evolution of life-history traits in host species.

  5. Microbial abundance on the eggs of a passerine bird and related fitness consequences between urban and rural habitats.

    Science.gov (United States)

    Lee, Sang-Im; Lee, Hyunna; Jablonski, Piotr G; Choe, Jae Chun; Husby, Magne

    2017-01-01

    Urban environments present novel and challenging habitats to wildlife. In addition to well-known difference in abiotic factors between rural and urban environments, the biotic environment, including microbial fauna, may also differ significantly. In this study, we aimed to compare the change in microbial abundance on eggshells during incubation between urban and rural populations of a passerine bird, the Eurasian Magpie (Pica pica), and examine the consequences of any differences in microbial abundances in terms of hatching success and nestling survival. Using real-time PCR, we quantified the abundances of total bacteria, Escherichia coli/Shigella spp., surfactin-producing Bacillus spp. and Candida albicans on the eggshells of magpies. We found that urban magpie eggs harboured greater abundances of E. coli/Shigella spp. and C. albicans before incubation than rural magpie eggs. During incubation, there was an increase in the total bacterial load, but a decrease in C. albicans on urban eggs relative to rural eggs. Rural eggs showed a greater increase in E. coli/Shigella spp. relative to their urban counterpart. Hatching success of the brood was generally lower in urban than rural population. Nestling survival was differentially related with the eggshell microbial abundance between urban and rural populations, which was speculated to be the result of the difference in the strength of the interaction among the microbes. This is the first demonstration that avian clutches in urban and rural populations differ in eggshell microbial abundance, which can be further related to the difference in hatching success and nestling survival in these two types of environments. We suggest that future studies on the eggshell microbes should investigate the interaction among the microbes, because the incubation and/or environmental factors such as urbanization or climate condition can influence the dynamic interactions among the microbes on the eggshells which can further determine the

  6. Linking phenological events in migratory passerines with a changing climate: 50 years in the Laurel Highlands of Pennsylvania.

    Science.gov (United States)

    McDermott, Molly E; DeGroote, Lucas W

    2017-01-01

    Advanced timing of both seasonal migration and reproduction in birds has been strongly associated with a warming climate for many bird species. Phenological responses to climate linking these stages may ultimately impact fitness. We analyzed five decades of banding data from 17 migratory bird species to investigate 1) how spring arrival related to timing of breeding, 2) if the interval between arrival and breeding has changed with increasing spring temperatures, and 3) whether arrival timing or breeding timing best predicted local productivity. Four of 17 species, all mid- to long-distance migrants, hatched young earlier in years when migrants arrived earlier to the breeding grounds (~1:1 day advancement). The interval between arrival on breeding grounds and appearance of juveniles shortened with warmer spring temperatures for 12 species (1-6 days for every 1°C increase) and over time for seven species (1-8 days per decade), suggesting that some migratory passerines adapt to climate change by laying more quickly after arrival or reducing the time from laying to fledging. We found more support for the former, that the rate of reproductive advancement was higher than that for arrival in warm years. Timing of spring arrival and breeding were both poor predictors of avian productivity for most migrants analyzed. Nevertheless, we found evidence that fitness benefits may occur from shifts to earlier spring arrival for the multi-brooded Song Sparrow. Our results uniquely demonstrate that co-occurring avian species are phenologically plastic in their response to climate change on their breeding grounds. If migrants continue to show a weaker response to temperatures during migration than breeding, and the window between arrival and optimal breeding shortens further, biological constraints to plasticity may limit the ability of species to adapt successfully to future warming.

  7. Linking phenological events in migratory passerines with a changing climate: 50 years in the Laurel Highlands of Pennsylvania.

    Directory of Open Access Journals (Sweden)

    Molly E McDermott

    Full Text Available Advanced timing of both seasonal migration and reproduction in birds has been strongly associated with a warming climate for many bird species. Phenological responses to climate linking these stages may ultimately impact fitness. We analyzed five decades of banding data from 17 migratory bird species to investigate 1 how spring arrival related to timing of breeding, 2 if the interval between arrival and breeding has changed with increasing spring temperatures, and 3 whether arrival timing or breeding timing best predicted local productivity. Four of 17 species, all mid- to long-distance migrants, hatched young earlier in years when migrants arrived earlier to the breeding grounds (~1:1 day advancement. The interval between arrival on breeding grounds and appearance of juveniles shortened with warmer spring temperatures for 12 species (1-6 days for every 1°C increase and over time for seven species (1-8 days per decade, suggesting that some migratory passerines adapt to climate change by laying more quickly after arrival or reducing the time from laying to fledging. We found more support for the former, that the rate of reproductive advancement was higher than that for arrival in warm years. Timing of spring arrival and breeding were both poor predictors of avian productivity for most migrants analyzed. Nevertheless, we found evidence that fitness benefits may occur from shifts to earlier spring arrival for the multi-brooded Song Sparrow. Our results uniquely demonstrate that co-occurring avian species are phenologically plastic in their response to climate change on their breeding grounds. If migrants continue to show a weaker response to temperatures during migration than breeding, and the window between arrival and optimal breeding shortens further, biological constraints to plasticity may limit the ability of species to adapt successfully to future warming.

  8. Endemic human fasciolosis in the Bolivian Altiplano.

    Science.gov (United States)

    Parkinson, M; O'Neill, S M; Dalton, J P

    2007-05-01

    Fasciolosis, caused by trematodes of the genus Fasciola, is an emerging disease of humans. One of the highest levels of human fasciolosis hepatica is found amongst the indigenous Aymaran people of the Northern Bolivian Altiplano. A meta-analysis of epidemiological surveys from 38 communities in the region demonstrates that fasciolosis has been endemic in the region since at least 1984 and is a zoonosis of rural communities. Human and bovine fasciolosis is associated with the communities lying in the plain from Lake Titicaca to La Paz, predominantly in the Los Andes province. In Los Andes incidences of up to 67% of population cohorts were found, and prevalence is age-related with the highest infection rate in children aged 8-11 years.

  9. Bursting endemic bubbles in an adaptive network

    Science.gov (United States)

    Sherborne, N.; Blyuss, K. B.; Kiss, I. Z.

    2018-04-01

    The spread of an infectious disease is known to change people's behavior, which in turn affects the spread of disease. Adaptive network models that account for both epidemic and behavioral change have found oscillations, but in an extremely narrow region of the parameter space, which contrasts with intuition and available data. In this paper we propose a simple susceptible-infected-susceptible epidemic model on an adaptive network with time-delayed rewiring, and show that oscillatory solutions are now present in a wide region of the parameter space. Altering the transmission or rewiring rates reveals the presence of an endemic bubble—an enclosed region of the parameter space where oscillations are observed.

  10. ANTIGENAEMIA AS AN INDICATOR OF FILARIAL ENDEMICITY

    Directory of Open Access Journals (Sweden)

    F. Partono

    2012-09-01

    Full Text Available This is a report of 1 -year evaluation of chemotherapeutic intervention in an area of Indonesia endemic for lymphatic filariasis. Control measures were initiated in 1977 by parasite control, informal health educa­tion, and community participation at the village level, well in accord with the WHO-concept of health for all. Diethylcarbamazine (DEC was mass distributed in 1977 and 1988, and selectively distributed in 1978, 1979, 1981, and 1982 to those who were micro-filaraemic prior to DEC treatments, those with a history of adenoly mphangitis over the previous one year period, and to all new comers. In addition, each villager with acute symptoms of adenolymphangitis was immediately treated with a single course of 300 mg DEC for 10 days. No intervention measures were taken between 1982 to 1988, and no attempt was taken to control the vector or to restrict movement between controlled and uncontrolled areas during the whole studies. With these measures, the microfilaria (mf rate decreased from 30% to 0%, the adenolymphangitis rate from 46% to 11%, and the elephantiasis rate from 35% to 3%. The abatement of acute and chronic filarial symptoms over the study period and the disappearance of microfilaremia in the community are pointing towards the possibility of eradicating the partasite from the community. To test this hypothesis, serum samples were tested for circulating filarial antigen by a two-site antigen capture assay employing anti-phosphorylcholine monoclonal antibodies. There was a sharp fall in circulating antigenaemia, demonstrating that infection has either been eliminated from nearly all villagers, or that intensity of infection is now undetectably low. We feel that antigenaemia can be used as an indicator of filarial endemicity.

  11. Comparative phylogeography of endemic Azorean arthropods.

    Science.gov (United States)

    Parmakelis, Aristeidis; Rigal, François; Mourikis, Thanos; Balanika, Katerina; Terzopoulou, Sofia; Rego, Carla; Amorim, Isabel R; Crespo, Luís; Pereira, Fernando; Triantis, Kostas A; Whittaker, Robert J; Borges, Paulo A V

    2015-11-11

    For a remote oceanic archipelago of up to 8 Myr age, the Azores have a comparatively low level of endemism. We present an analysis of phylogeographic patterns of endemic Azorean island arthropods aimed at testing patterns of diversification in relation to the ontogeny of the archipelago, in order to distinguish between alternative models of evolutionary dynamics on islands. We collected individuals of six species (representing Araneae, Hemiptera and Coleoptera) from 16 forest fragments from 7 islands. Using three mtDNA markers, we analysed the distribution of genetic diversity within and between islands, inferred the differentiation time-frames and investigated the inter-island migration routes and colonization patterns. Each species exhibited very low levels of mtDNA divergence, both within and between islands. The two oldest islands were not strongly involved in the diffusion of genetic diversity within the archipelago. The most haplotype-rich islands varied according to species but the younger, central islands contributed the most to haplotype diversity. Colonization events both in concordance with and in contradiction to an inter-island progression rule were inferred, while a non-intuitive pattern of colonization from western to eastern islands was also inferred. The geological development of the Azores has followed a less tidy progression compared to classic hotspot archipelagos, and this is reflected in our findings. The study species appear to have been differentiating within the Azores for <2 Myr, a fraction of the apparent life span of the archipelago, which may indicate that extinction events linked to active volcanism have played an important role. Assuming that after each extinction event, colonization was initiated from a nearby island hosting derived haplotypes, the apparent age of species diversification in the archipelago would be moved closer to the present after each extinction-recolonization cycle. Exploiting these ideas, we propose a general

  12. Features of Acquired Immunity in Malaria Endemic Areas

    Indian Academy of Sciences (India)

    ... of Acquired Immunity in Malaria Endemic Areas. Adults (>15 years) do not suffer from the disease. Concomitant presence of low levels of P. falciparum in immune persons. This immunity is lost within 6-12 months if a person moves out of endemic area. Antibodies mediate protection for the asexual stages of P. falciparum.

  13. Balancing forest-regeneration probabilities and maintenance costs in dry grasslands of high conservation priority

    Science.gov (United States)

    Bolliger, Janine; Edwards, Thomas C.; Eggenberg, Stefan; Ismail, Sascha; Seidl, Irmi; Kienast, Felix

    2011-01-01

    Abandonment of agricultural land has resulted in forest regeneration in species-rich dry grasslands across European mountain regions and threatens conservation efforts in this vegetation type. To support national conservation strategies, we used a site-selection algorithm (MARXAN) to find optimum sets of floristic regions (reporting units) that contain grasslands of high conservation priority. We sought optimum sets that would accommodate 136 important dry-grassland species and that would minimize forest regeneration and costs of management needed to forestall predicted forest regeneration. We did not consider other conservation elements of dry grasslands, such as animal species richness, cultural heritage, and changes due to climate change. Optimal sets that included 95–100% of the dry grassland species encompassed an average of 56–59 floristic regions (standard deviation, SD 5). This is about 15% of approximately 400 floristic regions that contain dry-grassland sites and translates to 4800–5300 ha of dry grassland out of a total of approximately 23,000 ha for the entire study area. Projected costs to manage the grasslands in these optimum sets ranged from CHF (Swiss francs) 5.2 to 6.0 million/year. This is only 15–20% of the current total estimated cost of approximately CHF30–45 million/year required if all dry grasslands were to be protected. The grasslands of the optimal sets may be viewed as core sites in a national conservation strategy.

  14. Grassland futures in Great Britain - Productivity assessment and scenarios for land use change opportunities.

    Science.gov (United States)

    Qi, Aiming; Holland, Robert A; Taylor, Gail; Richter, Goetz M

    2018-09-01

    To optimise trade-offs provided by future changes in grassland use intensity, spatially and temporally explicit estimates of respective grassland productivities are required at the systems level. Here, we benchmark the potential national availability of grassland biomass, identify optimal strategies for its management, and investigate the relative importance of intensification over reversion (prioritising productivity versus environmental ecosystem services). Process-conservative meta-models for different grasslands were used to calculate the baseline dry matter yields (DMY; 1961-1990) at 1km 2 resolution for the whole UK. The effects of climate change, rising atmospheric [CO 2 ] and technological progress on baseline DMYs were used to estimate future grassland productivities (up to 2050) for low and medium CO 2 emission scenarios of UKCP09. UK benchmark productivities of 12.5, 8.7 and 2.8t/ha on temporary, permanent and rough-grazing grassland, respectively, accounted for productivity gains by 2010. By 2050, productivities under medium emission scenario are predicted to increase to 15.5 and 9.8t/ha on temporary and permanent grassland, respectively, but not on rough grassland. Based on surveyed grassland distributions for Great Britain in 2010 the annual availability of grassland biomass is likely to rise from 64 to 72milliontonnes by 2050. Assuming optimal N application could close existing productivity gaps of ca. 40% a range of management options could deliver additional 21∗10 6 tonnes of biomass available for bioenergy. Scenarios of changes in grassland use intensity demonstrated considerable scope for maintaining or further increasing grassland production and sparing some grassland for the provision of environmental ecosystem services. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Species-rich semi-natural grasslands have a higher resistance but a lower resilience than intensively managed agricultural grasslands in response to climate anomalies

    NARCIS (Netherlands)

    Keersmaecker, De Wanda; Rooijen, van Nils; Lhermitte, Stef; Tits, Laurent; Schaminée, Joop; Coppin, Pol; Honnay, Olivier; Somers, Ben

    2016-01-01

    The stable delivery of ecosystem services provided by grasslands is strongly dependent on the stability of grassland ecosystem functions such as biomass production. Biomass production is in turn strongly affected by the frequency and intensity of climate extremes. The aim of this study is to

  16. Organohalogen contamination in passerine birds from three metropolises in China: Geographical variation and its implication for anthropogenic effects on urban environments

    International Nuclear Information System (INIS)

    Yu, Le-Huan; Luo, Xiao-Jun; Liu, Hong-Ying; Zeng, Yan-Hong; Zheng, Xiao-Bo; Wu, Jiang-Ping; Yu, Yun-Jiang; Mai, Bi-Xian

    2014-01-01

    Contamination of organohalogen pollutants (OHPs), including dichlorodiphenyl trichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenylethane (DBDPE), hexabromocyclododecanes (HBCDs), and dechlorane plus (DP) in three metropolises of China, Beijing, Wuhan, and Guangzhou, and a reference rural site were determined using terrestrial residential passerine species as bioindicator. DDTs dominated in Wuhan whereas flame retardants dominated in Guangzhou and Beijing. No geographical variation was found for PCB levels but it exhibited different homologue profiles among different sites which could be attributed to different dietary sources of birds. Industry characteristics of the sampling location contributed to the geographical differences in the occurrence and contamination profile of OHPs. The transformation of traditional agriculture characterized contamination profiles to industry characterized profiles in Beijing and Guangzhou implicates significantly environmental concern on the flame retardants contamination in non-hot-spot regions of China. - Highlights: • Various OHPs were determined in passerine birds from three metropolises of China. • Geographical variations of OHPs levels and contamination profiles were observed. • More concern should be taken on the dominance of FRs in Chinese developed cities. • Diet source characterized by δ 13 C plays a key role in PCB pattern determination. - Geographical variations of OHPs contamination profiles indicate significant impact of industrialization and urbanization on Chinese urban environment

  17. Endemic earthworms (Oligochaeta: Lumbricidae) of the Balkan Peninsula: a review.

    Science.gov (United States)

    Trakić, Tanja; Valchovski, Hristo; Stojanović, Mirjana

    2016-11-10

    A list of the endemic earthworms of the Balkan Peninsula is presented. Comprehensive information on the ecology, distribution on the Balkan Peninsula and zoogeographical type of all endemics is given. The list comprises 90 species and subspecies, belonging to 11 genera of the family Lumbricidae. The largest number of the Balkan endemic earthworms belongs to a narrow range group (63.3%). Broad range endemic species take part with 36.7%. Our study shows that the degree of endemism on the Balkan Peninsula is extremely high (about 40%) suggesting an important process of autochthonous speciation on the Balkan Peninsula. This appearance is attributable to relative isolation of the mountains compared to the lowlands within the context of paleoenvironmental changes.

  18. Endemism hotspots are linked to stable climatic refugia.

    Science.gov (United States)

    Harrison, Susan; Noss, Reed

    2017-01-01

    Centres of endemism have received much attention from evolutionists, biogeographers, ecologists and conservationists. Climatic stability is often cited as a major reason for the occurrences of these geographic concentrations of species which are not found anywhere else. The proposed linkage between endemism and climatic stability raises unanswered questions about the persistence of biodiversity during the present era of rapidly changing climate. The current status of evidence linking geographic centres of endemism to climatic stability over evolutionary time was examined. The following questions were asked. Do macroecological analyses support such an endemism-stability linkage? Do comparative studies find that endemic species display traits reflecting evolution in stable climates? Will centres of endemism in microrefugia or macrorefugia remain relatively stable and capable of supporting high biological diversity into the future? What are the implications of the endemism-stability linkage for conservation? Recent work using the concept of climate change velocity supports the classic idea that centres of endemism occur where past climatic fluctuations have been mild and where mountainous topography or favourable ocean currents contribute to creating refugia. Our knowledge of trait differences between narrow endemics and more widely distributed species remains highly incomplete. Current knowledge suggests that centres of endemism will remain relatively climatically buffered in the future, with the important caveat that absolute levels of climatic change and species losses in these regions may still be large. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. The Vegetation of North-Western Mongolia: Floristic Checklist and Conservation Status of Mongolian Grassland Flora

    Directory of Open Access Journals (Sweden)

    Katharina Lapin

    2017-05-01

    Full Text Available Mongolia´s grassland (steppe is reported to be vulnerable to climate change, degradation, and densifi cation. The traditional Mongolian pastoral herding system is currently transforming due to changes in market relations and economic developments, and this transformation has an impact on species composition and biodiversity. For this study, we observed the current situation of the fl ora in the north-western Mongolian territories to provide data on plant species occurrence in this remote area. A vegetation assessment was conducted for 15 locations in June and July 2016. Indicator plant species were determined to assess the level of grazing and degradation, as well as the respective steppe sub-type. The conservation status of all recorded plant species was assessed in accordance with the IUCN Red List. In total, 106 vascular plant species belonging to 73 genera and 26 families were recorded. Four endemic plant species were observed. All locations were classifi ed into three steppe sub-types: Desert-steppe, dry-steppe and mountain-steppe. A large number of degradation indicator plant species were observed in almost all locations. No endangered species in the Mongolian IUCN Red List were observed. The observation indicates that the vegetation in the north-western area of Mongolia is partly showing tendencies towards overgrazing and degradation. The conservation status of the most recorded species is currently unknown, and more studies on Mongolian vegetation will need to be conducted to assess these species’ status. We emphasize the urgent need for further studies on the vegetation and plant species composition, and indicators in north-western Mongolia, especially in context of the ongoing rapid economic, social, and ecological changes in the region

  20. Terrestrial ecology. Comprehensive study of the grassland biome

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Terrestrial ecology and grassland biome studies are designed to characterize the biota of the Hanford Reservation, elucidate seasonal dynamics of plant productivity, decomposition and mineral behavior patterns of important plant communities, and, to study the response of these communities to important natural environmental stresses, such as weather, wildfire and man-induced alterations of communities (influenced by grazing cattle and severe mechanical disturbance of the soil, such as affected by plowing or burial of waste materials or construction activities). A detailed account of the important findings of a 5-yr study is currently being prepared by the terrestrial ecology section staff for publication as a contribution to the International Biological Program Grassland Biome project

  1. Herbivores and nutrients control grassland plant diversity via light limitation

    Science.gov (United States)

    Borer, Elizabeth T.; Seabloom, Eric W.; Gruner, Daniel S.; Harpole, W. Stanley; Hillebrand, Helmut; Lind, Eric M.; Alder, Peter B.; Alberti, Juan; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori; Blumenthal, Dana; Brown, Cynthia S.; Brudvig, Lars A.; Buckley, Yvonne M.; Cadotte, Marc; Chu, Cheng-Jin; Cleland, Elsa E.; Crawley, Michael J.; Daleo, Pedro; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Du, Guozhen; Firn, Jennifer; Hautier, Yann; Heckman, Robert W.; Hector, Andy; HilleRisLambers, Janneke; Iribarne, Oscar; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Leakey, Andrew D.B.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Mortensen, Brent; O'Halloran, Lydia R.; Orrock, John L.; Pascual, Jesús; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Williams, Ryan J.; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

    2014-01-01

    Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  2. Direct effects of cattle on grassland birds in Canada.

    Science.gov (United States)

    Bleho, Barbara I; Koper, Nicola; Machtans, Craig S

    2014-06-01

    Effects of grazing on grassland birds are generally thought to be indirect, through alteration of vegetation structure; however, livestock can also affect nest survival directly through trampling and other disturbances (e.g., livestock-induced abandonment). We extracted data on nest fates from 18 grazing studies conducted in Canada. We used these data to assess rates of nest destruction by cattle among 9 ecoregions and between seasonal and rotational grazing systems. Overall, few nests were destroyed by cattle (average 1.5% of 9132 nests). Nest destruction was positively correlated with grazing pressure (i.e., stocking rate or grazing intensity), but nest survival was higher in more heavily grazed areas for some species. Because rates of destruction of grassland bird nests by cattle are low in Canada, management efforts to reduce such destruction may not be of ecological or economic value in Canada. © 2014 Society for Conservation Biology.

  3. The biological transport of radionuclides in grassland and freshwater ecosystems

    International Nuclear Information System (INIS)

    Rudge, S.A.

    1989-12-01

    This thesis examines the biological transport of radionuclides through terrestrial and aquatic ecosystems, with particular reference to radiocaesium. The semi-natural grassland habitat was located at Drigg, W. Cumbria, contaminated primarily by radioactive fallout, from several sources over the past decade. Advantage was made of the deposition of radionuclides from the Chernobyl reactor incident, which occurred during the early stages of the investigation. The study examined the distribution of radiocaesium for the major components of the grassland ecosystem, within the soil-plant-invertebrate-small mammal food chain. Data concerning temporal fluctuation of radionuclide transfer factors between food chain components are presented. The final section examines the spatial distribution of radiocaesium in sediment and the freshwater eel (Anguilla anguilla) in a small stream contaminated by radioactive effluent. The relationship between activity levels in eels and the sediments in which they rest and forage was investigated. Factors influencing uptake of radiocaesium in freshwater fish were also examined. (author)

  4. Acidification of sandy grasslands - consequences for plant diversity

    DEFF Research Database (Denmark)

    Olsson, Pål Axel; Mårtensson, Linda-Maria; Bruun, Hans Henrik

    2009-01-01

    soil; a number of nationally red-listed species showed a similar pattern. Plant species diversity and number of red-listed species increased with slope. Where the topsoil had been acidified, limestone was rarely present above a depth of 30 cm. The presence of limestone restricts the availability......Questions: (1) Does soil acidification in calcareous sandy grasslands lead to loss of plant diversity? (2) What is the relationship between the soil content of lime and the plant availability of mineral nitrogen (N) and phosphorus (P) in sandy grasslands? Location: Sandy glaciofluvial deposits......). Environmental variables were recorded at each plot, and soil samples were analysed for exchangeable P and N, as well as limestone content and pH. Data were analysed with regression analysis and canonical correspondence analysis. Results: Plant species richness was highest on weakly acid to slightly alkaline...

  5. Species interactions reverse grassland responses to changing climate.

    Science.gov (United States)

    Suttle, K B; Thomsen, Meredith A; Power, Mary E

    2007-02-02

    Predictions of ecological response to climate change are based largely on direct climatic effects on species. We show that, in a California grassland, species interactions strongly influence responses to changing climate, overturning direct climatic effects within 5 years. We manipulated the seasonality and intensity of rainfall over large, replicate plots in accordance with projections of leading climate models and examined responses across several trophic levels. Changes in seasonal water availability had pronounced effects on individual species, but as precipitation regimes were sustained across years, feedbacks and species interactions overrode autecological responses to water and reversed community trajectories. Conditions that sharply increased production and diversity through 2 years caused simplification of the food web and deep reductions in consumer abundance after 5 years. Changes in these natural grassland communities suggest a prominent role for species interactions in ecosystem response to climate change.

  6. Urinary iodine excretion in relation to goiter prevalence in households of goiter endemic and non endemic regions of Ethiopia

    International Nuclear Information System (INIS)

    Abuye, Chernet; Hailemariam, Bantiyrgu; Neka Tibeb, Hanna; Urga, Kelbesa; Woldegebriel, Zewidie

    1995-01-01

    A Survey of goiter prevalence, among population of five endemic and four non endemic regions of Ethiopia was carried out prior to the distribution of iodate d salt. urine samples were collected from 327 subjects selected by systematic random sampling from endemic and 276 taken as non endemic. The lowest mean urinary iodine excretion (UIE) value was recorded in Bure (22 micro gl/day) and the highest in Alemmaya (148 micro gl/day). The highest goiter rate ( percent TGR) was recorded in Sawla 55.6 %) and the lowest (0.6 %) in Yabello. Iodine content of drinking was in the range of 0.4 - 48.5 micro gl. Iodine content of water source was correlated positively ( r0.8399) with the mean of UIE and TGR, however, indicates that sites considered as non endemic seem to be affected by iodine deficiency. The study results urge the need for intervention in controlling Iodine Deficiency Disorders. 3 tab

  7. Composition, phenology and restoration of campo rupestre mountain grasslands - Brazil

    OpenAIRE

    Le Stradic, Soizig

    2012-01-01

    Global environmental changes, especially land-use changes, have profound effects on both ecosystem functioning and biodiversity, having already altered many ecosystem services. These losses emphasize the need to preserve what remains; however when conservation programs are not sufficient, restoring areas that have been destroyed or disturbed can improve conservation efforts and mitigate damages. This work focuses on campos rupestres, Neotropical grasslands found at altitudes, which are part o...

  8. Carbon dynamics in an Imperata grassland in Northeast India

    Directory of Open Access Journals (Sweden)

    Amrabati Thokchom

    2016-01-01

    Full Text Available Carbon stocks and soil CO2 flux were assessed in an Imperata cylindrica grassland of Manipur, Northeast India. Carbon stocks in the vegetative components were estimated to be 11.17 t C/ha and soil organic carbon stocks were 55.94 t C/ha to a depth of 30 cm. The rates of carbon accumulation in above-ground and below-ground biomass were estimated to be 11.85 t C/ha/yr and 11.71 t C/ha/yr, respectively. Annual soil CO2 flux was evaluated as 6.95 t C/ha and was highly influenced by soil moisture, soil temperature and soil organic carbon as well as by C stocks in above-ground biomass. Our study on the carbon budget of the grassland ecosystem revealed that annually 23.56 t C/ha was captured by the vegetation through photosynthesis, and 6.95 t C/ha was returned to the atmosphere through roots and microbial respiration, with a net balance of 16.61 t C/ha/yr being retained in the grassland ecosystem. Thus the present Imperata grassland exhibited a high capacity to remove atmospheric CO2 and to induce high C stocks in the soil provided it is protected from burning and overgrazing.Keywords: Above-ground biomass, below-ground biomass, carbon stocks, carbon storage, net primary productivity, soil CO2 flux.DOI: 10.17138/TGFT(419-28  

  9. Carbon balance of renovated grasslands: input- or output-driven?

    Science.gov (United States)

    Choncubhair, Órlaith Ní; Osborne, Bruce; Lanigan, Gary

    2015-04-01

    Temperate grasslands constitute over 30% of the Earth's naturally-occurring biomes and make an important contribution towards the partial mitigation of anthropogenic greenhouse gas emissions by terrestrial ecosystems. In permanent temperate grasslands, biomass production and sward quality can deteriorate over time and periodic renovation activities, involving soil tillage and reseeding, are commonly carried out to halt this decline. Long-term cultivation of agricultural land has been associated with soil aggregate degradation and reduced soil carbon storage. However, the impact of these single tillage disturbances on C cycling in grasslands is less clear. This study evaluated gaseous and dissolved organic carbon (DOC) losses following a single tillage event by subjecting grassland lysimeters with contrasting soil drainage characteristics to simulated conventional inversion or minimum tillage. Field-scale CO2 emissions after conventional tillage were also quantified and empirically modelled over short- and medium-term timeframes to delineate the ecosystem response to environmental variables. Soil moisture was the limiting determinant of ecosystem carbon release following conventional tillage. Freshly-tilled soils were associated with reduced water retention and increased sensitivity to soil moisture, which was particularly pronounced following rewetting events. Significantly elevated but ephemeral CO2 effluxes were detected in the hours following inversion ploughing, however tillage disturbance did not generate significantly enhanced C emission rates in the medium term. Equally, DOC losses were not significantly amplified by conventional tillage compared with conservative minimum tillage and were predominantly controlled by soil drainage across tillage regimes. Our results suggest that a net ecosystem source of 120 to 210 g C m-2 over an approximately two-month period was most likely a consequence of reduced productivity and C input rather than enhanced soil CO2

  10. Making Grasslands Sustainable in Mongolia: Herders' Livelihoods and Climate Change

    OpenAIRE

    Asian Development Bank (ADB)

    2014-01-01

    The threats posed by climate change have significant impacts on Mongolia’s grassland ecosystems and herders’ livelihoods. This publication discusses the auses of climate change and its impacts on livelihoods and ecosystems for herders and the general public. It explains how good pasture management and livestock roductivity are important for increasing incomes and provides information on adaptation practices. It also identifies sustainable management practices that can increase communities’ re...

  11. Hierarchical traits distances explain grassland Fabaceae species' ecological niches distances

    Science.gov (United States)

    Fort, Florian; Jouany, Claire; Cruz, Pablo

    2015-01-01

    Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e., ecological niches. We measured a wide range of functional traits (root traits, leaf traits, and whole plant traits) in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species' ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems) are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems) are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance. PMID:25741353

  12. Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    Full Text Available Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2.s(-1 and clipping (2.06 μmol.m(-2.s(-1 than under grazing (1.65 μmol.m-(2.s(-1 over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP. Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content and biotic (ANPP and BNPP factors regulate soil respiration in the semiarid temperate grassland of northern China.

  13. Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.

    Science.gov (United States)

    Wang, Zhen; Ji, Lei; Hou, Xiangyang; Schellenberg, Michael P

    2016-01-01

    Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures) on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2).s(-1)) and clipping (2.06 μmol.m(-2).s(-1)) than under grazing (1.65 μmol.m-(2).s(-1)) over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP). Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP) and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content) and biotic (ANPP and BNPP) factors regulate soil respiration in the semiarid temperate grassland of northern China.

  14. Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances

    Directory of Open Access Journals (Sweden)

    Florian eFort

    2015-02-01

    Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.

  15. Evaluation of semiarid grassland degradation in North China from multiple perspectives

    Science.gov (United States)

    Han, D.; Wang, G.; Xue, B. L.; Xu, X.

    2017-12-01

    There has been increasing interest in grassland ecosystem degradation resulting from intensive human activity and climate change, especially in arid and semiarid regions. Species composition, grassland desertification, and aboveground biomass (AGB) are used as indicators of grassland degradation in this study. We comprehensively analyzed variations in these three indicators in semiarid grassland in North China, on multiple time scales, based on MODIS products and field sampling datasets. Since 1984, species composition has become simpler and species indicative of grassland degradation, such as Potentilla acaulis and Artemisia frigida, have become dominant. These changes indicate that serious grassland degradation has occurred since 1984. Grassland degradation was also analyzed on shorter time scales. Analyses of interannual variations during 2005-2015 showed that desertification decreased and average AGB in the growth season increased over the study area, indicating that grassland was recovering. Analyses of spatial variations showed that the position of slightly desertified grassland shifted and formed a band in the west, where the lowest AGB in the growth season was recorded but tendency ratio of AGB increased from 2005 to 2015. Climatic factors had critical effects on grassland degradation, as identified by the three indicators on different time scales. The simpler species composition resulted from the increase in average temperature and decrease in average precipitation over the past 30 years. For nearly a decade, an increase in precipitation and decreases in temperature and potential evapotranspiration reduced desertification and increased AGB in the growth season overall. Consequently, there has distinct difference in grassland degradation between analysis results on above two time scales, indicating multiple perspectives should be considered to accurately assess the state and characteristics of grassland degradation.

  16. Exacerbated grassland degradation and desertification in Central Asia during 2000-2014.

    Science.gov (United States)

    Zhang, Geli; Biradar, Chandrashekhar M; Xiao, Xiangming; Dong, Jinwei; Zhou, Yuting; Qin, Yuanwei; Zhang, Yao; Liu, Fang; Ding, Mingjun; Thomas, Richard J

    2018-03-01

    Grassland degradation and desertification is a complex process, including both state conversion (e.g., grasslands to deserts) and gradual within-state change (e.g., greenness dynamics). Existing studies hardly separated the two components and analyzed it as a whole based on time series vegetation index data, which cannot provide a clear and comprehensive picture for grassland degradation and desertification. Here we propose an integrated assessment strategy, by considering both state conversion and within-state change of grasslands, to investigate grassland degradation and desertification process in Central Asia. First, annual maps of grasslands and sparsely vegetated land were generated to track the state conversions between them. The results showed increasing grasslands were converted to sparsely vegetated lands from 2000 to 2014, with the desertification region concentrating in the latitude range of 43-48° N. A frequency analysis of grassland vs. sparsely vegetated land classification in the last 15 yr allowed a recognition of persistent desert zone (PDZ), persistent grassland zone (PGZ), and transitional zone (TZ). The TZ was identified in southern Kazakhstan as one hotspot that was unstable and vulnerable to desertification. Furthermore, the trend analysis of Enhanced Vegetation Index during thermal growing season (EVI TGS ) was investigated in individual zones using linear regression and Mann-Kendall approaches. An overall degradation across the area was found; moreover, the second desertification hotspot was identified in northern Kazakhstan with significant decreasing in EVI TGS , which was located in PGZ. Finally, attribution analyses of grassland degradation and desertification were conducted by considering precipitation, temperature, and three different drought indices. We found persistent droughts were the main factor for grassland degradation and desertification in Central Asia. Considering both state conversion and gradual within-state change

  17. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass

    Directory of Open Access Journals (Sweden)

    Fengge Zhang

    2018-04-01

    Full Text Available In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly (p = 0.019 increased following amendment with 9,000 kg ha−1 of Trichoderma biofertilizer (composted cattle manure + inoculum compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha−1 biofertilizer. This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha−1 increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella. Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella. According to our structural equation modeling (SEM, Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  18. Impacts of tree rows on grassland birds and potential nest predators: a removal experiment.

    Science.gov (United States)

    Ellison, Kevin S; Ribic, Christine A; Sample, David W; Fawcett, Megan J; Dadisman, John D

    2013-01-01

    Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow's sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus]) at sites in Wisconsin, U.S.A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2-4 times for bobolink and Henslow's sparrow) and nesting densities increased (all 3 species) in the removal areas compared to control areas. After removals, Henslow's sparrows nested within ≤50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor]) at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]). Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116) and the number of successful nests for bobolinks and Henslow's sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland ecosystems.

  19. Impacts of tree rows on grassland birds and potential nest predators: a removal experiment.

    Directory of Open Access Journals (Sweden)

    Kevin S Ellison

    Full Text Available Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow's sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus] at sites in Wisconsin, U.S.A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2-4 times for bobolink and Henslow's sparrow and nesting densities increased (all 3 species in the removal areas compared to control areas. After removals, Henslow's sparrows nested within ≤50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor] at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]. Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116 and the number of successful nests for bobolinks and Henslow's sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland

  20. The influence of boundary features on grassland-edge communities of Alta Murgia

    OpenAIRE

    Cassano, Stefania; Alignier, Audrey; Forte, Luigi; Labadessa, Rocco; Mairota, Paola

    2016-01-01

    Many studies suggest the importance of boundary features on plant community dynamics. Our aim was to investigate the influence of boundary features on edge plant assemblages in semi-natural dry grasslands. For this purpose we selected 16 grassland edges in the central portion of the Natura 2000 site Murgia Alta, in southeastern Italy. These sites were selected according to a combination of boundary features, i.e. the adjoining land use type (road or cereal crop), slope (grassland tilted towar...

  1. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass.

    Science.gov (United States)

    Zhang, Fengge; Huo, Yunqian; Cobb, Adam B; Luo, Gongwen; Zhou, Jiqiong; Yang, Gaowen; Wilson, Gail W T; Zhang, Yingjun

    2018-01-01

    In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly ( p = 0.019) increased following amendment with 9,000 kg ha -1 of Trichoderma biofertilizer (composted cattle manure + inoculum) compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha -1 biofertilizer). This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS) revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha -1 ) increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella . Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella . According to our structural equation modeling (SEM), Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  2. Costs of Illness Due to Endemic Cholera

    Science.gov (United States)

    Poulos, C.; Riewpaiboon, A.; Stewart, J.F.; Clemens, J.; Guh, S.; Agtini, M.; Sur, D.; Islam, Z.; Lucas, M.; Whittington, D.

    2013-01-01

    Summary Economic analyses of cholera immunization programmes require estimates of the costs of cholera. The Diseases of the Most Impoverished programme measured the public, provider, and patient costs of culture-confirmed cholera in four study sites with endemic cholera using a combination of hospital- and community-based studies. Families with culture-proven cases were surveyed at home 7 and 14 days after confirmation of illness. Public costs were measured at local health facilities using a micro-costing methodology. Hospital-based studies found that the costs of severe cholera were USD 32 and 47 in Matlab and Beira. Community-based studies in North Jakarta and Kolkata found that cholera cases cost between USD 28 and USD 206, depending on hospitalization. Patient costs of illness as a percentage of average monthly income were 21% and 65% for hospitalized cases in Kolkata and North Jakarta, respectively. This burden on families is not captured by studies that adopt a provider perspective. PMID:21554781

  3. Endemic pemphigus over a century: Part II.

    Science.gov (United States)

    Abréu-Vélez, Ana María; Roselino, Ana Maria; Howard, Michael S; Reason, Iara J de Messias

    2010-03-01

    Endemic pemphigus foliaceus (EPF) is an autoimmune disease, classically occurring in a restricted geographic area. Foci of EPF have been described in several Central and South American countries, often affecting young people and Amerindians, with some female predilection. Although most American EPF cases have been documented in Brazil, cases have been reported in Peru, Paraguay, El Salvador and Venezuela. An additional variant of EPF has been described in El Bagre, Colombia, (El Bagre-EPF) affecting older men and a few post-menopausal females. Finally, one additional type of EPF has been described in nomadic tribes affecting females of child bearing age in Tunisia, Africa. The main aim of this review is to summarize current knowledge about autoantigens, and immunologic and genetic studies in EPF. We utilized a retrospective review of the literature, aiming to compile and compare the multiple geographic foci of EPF. The primary autoantigens in EPF are still considered to be desmogleins in the case of the Tunisian and all American cases, in contradistinction to plakins and desmogleins in El Bagre-EPF. Although several autoantigens are been suggested, their biochemical nature needs further elucidation. Current knowledge still supports the concept that an antibody mediated immune response represents the principal pathophysiology in all variants of EPF. A strong genetic susceptibility appears to contribute to disease development in several people affected by these diseases; however, no specific genes have been confirmed at present. We conclude that further investigation is necessary to define these disorders immunologically and genetically.

  4. Updated Global Burden of Cholera in Endemic Countries

    Science.gov (United States)

    Ali, Mohammad; Nelson, Allyson R.; Lopez, Anna Lena; Sack, David A.

    2015-01-01

    Background The global burden of cholera is largely unknown because the majority of cases are not reported. The low reporting can be attributed to limited capacity of epidemiological surveillance and laboratories, as well as social, political, and economic disincentives for reporting. We previously estimated 2.8 million cases and 91,000 deaths annually due to cholera in 51 endemic countries. A major limitation in our previous estimate was that the endemic and non-endemic countries were defined based on the countries’ reported cholera cases. We overcame the limitation with the use of a spatial modelling technique in defining endemic countries, and accordingly updated the estimates of the global burden of cholera. Methods/Principal Findings Countries were classified as cholera endemic, cholera non-endemic, or cholera-free based on whether a spatial regression model predicted an incidence rate over a certain threshold in at least three of five years (2008-2012). The at-risk populations were calculated for each country based on the percent of the country without sustainable access to improved sanitation facilities. Incidence rates from population-based published studies were used to calculate the estimated annual number of cases in endemic countries. The number of annual cholera deaths was calculated using inverse variance-weighted average case-fatality rate (CFRs) from literature-based CFR estimates. We found that approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases (uncertainty range: 1.3m-4.0m) occur annually in endemic countries. Among these cases, there are an estimated 95,000 deaths (uncertainty range: 21,000-143,000). Conclusion/Significance The global burden of cholera remains high. Sub-Saharan Africa accounts for the majority of this burden. Our findings can inform programmatic decision-making for cholera control. PMID:26043000

  5. [Vegetation index estimation by chlorophyll content of grassland based on spectral analysis].

    Science.gov (United States)

    Xiao, Han; Chen, Xiu-Wan; Yang, Zhen-Yu; Li, Huai-Yu; Zhu, Han

    2014-11-01

    Comparing the methods of existing remote sensing research on the estimation of chlorophyll content, the present paper confirms that the vegetation index is one of the most practical and popular research methods. In recent years, the increasingly serious problem of grassland degradation. This paper, firstly, analyzes the measured reflectance spectral curve and its first derivative curve in the grasslands of Songpan, Sichuan and Gongger, Inner Mongolia, conducts correlation analysis between these two spectral curves and chlorophyll content, and finds out the regulation between REP (red edge position) and grassland chlorophyll content, that is, the higher the chlorophyll content is, the higher the REIP (red-edge inflection point) value would be. Then, this paper constructs GCI (grassland chlorophyll index) and selects the most suitable band for retrieval. Finally, this paper calculates the GCI by the use of satellite hyperspectral image, conducts the verification and accuracy analysis of the calculation results compared with chlorophyll content data collected from field of twice experiments. The result shows that for grassland chlorophyll content, GCI has stronger sensitivity than other indices of chlorophyll, and has higher estimation accuracy. GCI is the first proposed to estimate the grassland chlorophyll content, and has wide application potential for the remote sensing retrieval of grassland chlorophyll content. In addition, the grassland chlorophyll content estimation method based on remote sensing retrieval in this paper provides new research ideas for other vegetation biochemical parameters' estimation, vegetation growth status' evaluation and grassland ecological environment change's monitoring.

  6. Grassland birds wintering at U.S. Navy facilities in southern Texas

    Science.gov (United States)

    Woodin, Marc C.; Skoruppa, Mary Kay; Bryan, Pearce D.; Ruddy, Amanda J.; Hickman, Graham C.

    2010-01-01

    Grassland birds have undergone widespread decline throughout North America during the past several decades. Causes of this decline include habitat loss and fragmentation because of conversion of grasslands to cropland, afforestation in the East, brush and shrub invasion in the Southwest and western United States, and planting of exotic grass species to enhance forage production. A large number of exotic plant species, including grasses, have been introduced in North America, but most research on the effects of these invasions on birds has been limited to breeding birds, primarily those in northern latitudes. Research on the effects of exotic grasses on birds in winter has been extremely limited.This is the first study in southern Texas to examine and compare winter bird responses to native and exotic grasslands. This study was conducted during a period of six years (2003–2009) on United States Navy facilities in southern Texas including Naval Air Station–Corpus Christi, Naval Air Station–Kingsville, Naval Auxiliary Landing Field Waldron, Naval Auxiliary Landing Field Orange Grove, and Escondido Ranch, all of which contained examples of native grasslands, exotic grasslands, or both. Data from native and exotic grasslands were collected and compared for bird abundance and diversity; ground cover, vegetation density, and floristic diversity; bird and vegetation relationships; diversity of insects and arachnids; and seed abundance and diversity. Effects of management treatments in exotic grasslands were evaluated by comparing numbers and diversity of birds and small mammals in mowed, burned, and control areas.To determine bird abundance and bird species richness, birds were surveyed monthly (December–February) during the winters of 2003–2008 in transects (100 meter × 20 meter) located in native and exotic grasslands distributed at all five U.S. Navy facilities. To compare vegetation in native and exotic grasslands, vegetation characteristics were measured

  7. [Safety threshold of fluorine in endemic fluorosis regions in China].

    Science.gov (United States)

    Li, Yonghua; Wang, Wuyi; Hou, Shaofan

    2002-07-01

    Four endemic fluorosis regions in China and their environmental epidemiological characteristics were summarized in this paper. It shows that the epidemiology of endemic fluorosis is closely related to geochemical parameters of local environment. The food-web and dose-effect relationship of fluoride from environment to human body in different types of endemic fluorosis regions were studied. And the safety threshold of fluoride in different regions was determined. The results have provided a scientific basis for environmental risk assessment of fluoride in China.

  8. Estimating N2O processes during grassland renewal and grassland conversion to maize cropping using N2O isotopocules

    Science.gov (United States)

    Buchen, Caroline; Well, Reinhard; Flessa, Heinz; Fuß, Roland; Helfrich, Mirjam; Lewicka-Szczebak, Dominika

    2017-04-01

    Grassland break-up due to grassland renewal and grassland conversion to cropland can lead to a flush of mineral nitrogen from decomposition of the old grass sward and the decomposition of soil organic matter. Moreover, increased carbon and nitrogen mineralisation can result in enhanced nitrous oxide (N2O) emissions. As N2O is known to be an important greenhouse gas and a major precursor for ozone depletion, its emissions need to be mitigated by adjusting agricultural management practices. Therefore, it is necessary to understand the N2O processes involved, as well as the contribution of N2O reduction to N2. Apart from the widely used 15N gas flux method, natural abundance isotopic analysis of the four most abundant isotopocules of N2O species is a promising alternative to assess N2O production pathways. We used stable isotope analyses of soil-emitted N2O (δ18ON2O, δ15NN2Obulk and δ15NN2OSP= intramolecular distribution of 15N within the linear N2O molecule) with an isotopocule mapping approach to simultaneously estimate the magnitude of N2O reduction to N2 and the fraction of N2O originating from the bacterial denitrification pathway or fungal denitrification and/or nitrification. This approach is based on endmember areas of isotopic values for the N2O produced from different sources reported in the literature. For this purpose, we calculated two main scenarios with different assumptions for N2O produced: N2O is reduced to N2 before residual N2O is mixed with N2O of various sources (Scenario a) and vice versa (Scenario b). Based on this, we applied seven different scenario variations, where we evaluated the range of possible values for the potential N2O production pathways (heterotrophic bacterial denitrification and/or nitrifier denitrification and fungal denitrification and/or nitrification). This was done by using a range of isotopic endmember values and assuming different fractionation factors of N2O reduction in order to find the most reliable scenario

  9. Endemic infrared divergences in QED3 at finite temperature

    International Nuclear Information System (INIS)

    Lo, Pok Man; Swanson, Eric S.

    2011-01-01

    We demonstrate that massless QED in three dimensions contains endemic infrared divergences. It is argued that these divergences do not affect observables; furthermore, it is possible to choose a gauge that renders the theory finite.

  10. Chlamydia trachomatis serovars of endemic trachoma had been ...

    African Journals Online (AJOL)

    Journal of Applied Sciences and Environmental Management ... The serovars that we identified from Japanese infants and pregnant women ... Once Japan was thought to be belong to an endemic area of trachoma as other Asian countries.

  11. The dynamics of endemic malaria in populations of varying size

    International Nuclear Information System (INIS)

    Ngwa, G.A.

    2001-10-01

    A mathematical model for endemic malaria involving variable human and mosquito populations is analysed. A threshold parameter R 0 exists and the disease can persist if and only if R 0 exceeds 1. R 0 is seen to be a generalisation of the basic reproduction ratio associated with the Ross-Macdonald model for malaria transmission. The disease free equilibrium always exist and is globally stable when R 0 is below 1. A perturbation analysis is used to approximate the endemic equilibrium in the important case where the disease related death rate is nonzero. A diffusion approximation is used to approximate the quasi-stationary distribution of the associated stochastic model. Numerical simulations show that when R 0 is distinctly greater than 1, the endemic deterministic equilibrium is globally stable. Furthermore, in quasi-stationarity, the stochastic process undergoes oscillations about a mean population whose size can be approximated by the stable endemic deterministic equilibrium. (author)

  12. Spatial distribution of Madeira Island Laurisilva endemic spiders (Arachnida: Araneae)

    Science.gov (United States)

    2014-01-01

    Abstract Madeira island presents a unique spider diversity with a high number of endemic species, many of which are still poorly known. A recent biodiversity survey on the terrestrial arthropods of the native forest, Laurisilva, provided a large set of standardized samples from various patches throughout the island. Out of the fifty two species recorded, approximately 33.3% are Madeiran endemics, many of which had not been collected since their original description. Two new species to science are reported – Ceratinopsis n. sp. and Theridion n. sp. – and the first records of Poeciloneta variegata (Blackwall, 1841) and Tetragnatha intermedia Kulczynski, 1891 are reported for the first time for Madeira island. Considerations on species richness and abundance from different Laurisilva locations are presented, together with distribution maps for endemic species. These results contribute to a better understanding of spider diversity patterns and endemic species distribution in the native forest of Madeira island. PMID:24855443

  13. An Investigation on the antimicrobial activity of some endemic plant ...

    African Journals Online (AJOL)

    SERVER

    2008-01-04

    Jan 4, 2008 ... Key words: Antimicrobial activity, endemic plants, plant extract. INTRODUCTION ..... The essential oil of A. balsamea was found to be inactive against E. ... Origanum solymicum and Origanum bilgeri from Turkey. Afr. J. Trad.

  14. isoenzyme analysis of five endemic and one widespread kniphofia ...

    African Journals Online (AJOL)

    Preferred Customer

    ISOENZYME ANALYSIS OF FIVE ENDEMIC AND ONE WIDESPREAD ... plants. The over all mean inbreeding coefficient (F) was positive indicating slight deficiency in the number of ...... populations, indicates rather recent speciation.

  15. Flower resource and land management drives hoverfly communities and bee abundance in seminatural and agricultural grasslands.

    Science.gov (United States)

    Lucas, Andrew; Bull, James C; de Vere, Natasha; Neyland, Penelope J; Forman, Dan W

    2017-10-01

    Pollination is a key ecosystem service, and appropriate management, particularly in agricultural systems, is essential to maintain a diversity of pollinator guilds. However, management recommendations frequently focus on maintaining plant communities, with the assumption that associated invertebrate populations will be sustained. We tested whether plant community, flower resources, and soil moisture would influence hoverfly (Syrphidae) abundance and species richness in floristically-rich seminatural and floristically impoverished agricultural grassland communities in Wales (U.K.) and compared these to two Hymenoptera genera, Bombus, and Lasioglossum . Interactions between environmental variables were tested using generalized linear modeling, and hoverfly community composition examined using canonical correspondence analysis. There was no difference in hoverfly abundance, species richness, or bee abundance, between grassland types. There was a positive association between hoverfly abundance, species richness, and flower abundance in unimproved grasslands. However, this was not evident in agriculturally improved grassland, possibly reflecting intrinsically low flower resource in these habitats, or the presence of plant species with low or relatively inaccessible nectar resources. There was no association between soil moisture content and hoverfly abundance or species richness. Hoverfly community composition was influenced by agricultural improvement and the amount of flower resource. Hoverfly species with semiaquatic larvae were associated with both seminatural and agricultural wet grasslands, possibly because of localized larval habitat. Despite the absence of differences in hoverfly abundance and species richness, distinct hoverfly communities are associated with marshy grasslands, agriculturally improved marshy grasslands, and unimproved dry grasslands, but not with improved dry grasslands. Grassland plant community cannot be used as a proxy for pollinator

  16. A world malaria map: Plasmodium falciparum endemicity in 2007.

    Directory of Open Access Journals (Sweden)

    Simon I Hay

    2009-03-01

    Full Text Available Efficient allocation of resources to intervene against malaria requires a detailed understanding of the contemporary spatial distribution of malaria risk. It is exactly 40 y since the last global map of malaria endemicity was published. This paper describes the generation of a new world map of Plasmodium falciparum malaria endemicity for the year 2007.A total of 8,938 P. falciparum parasite rate (PfPR surveys were identified using a variety of exhaustive search strategies. Of these, 7,953 passed strict data fidelity tests for inclusion into a global database of PfPR data, age-standardized to 2-10 y for endemicity mapping. A model-based geostatistical procedure was used to create a continuous surface of malaria endemicity within previously defined stable spatial limits of P. falciparum transmission. These procedures were implemented within a Bayesian statistical framework so that the uncertainty of these predictions could be evaluated robustly. The uncertainty was expressed as the probability of predicting correctly one of three endemicity classes; previously stratified to be an informative guide for malaria control. Population at risk estimates, adjusted for the transmission modifying effects of urbanization in Africa, were then derived with reference to human population surfaces in 2007. Of the 1.38 billion people at risk of stable P. falciparum malaria, 0.69 billion were found in Central and South East Asia (CSE Asia, 0.66 billion in Africa, Yemen, and Saudi Arabia (Africa+, and 0.04 billion in the Americas. All those exposed to stable risk in the Americas were in the lowest endemicity class (PfPR2-10 5 to or = 40% areas. High endemicity was widespread in the Africa+ region, where 0.35 billion people are at this level of risk. Most of the rest live at intermediate risk (0.20 billion, with a smaller number (0.11 billion at low stable risk.High levels of P. falciparum malaria endemicity are common in Africa. Uniformly low endemic levels are

  17. A world malaria map: Plasmodium falciparum endemicity in 2007.

    Science.gov (United States)

    Hay, Simon I; Guerra, Carlos A; Gething, Peter W; Patil, Anand P; Tatem, Andrew J; Noor, Abdisalan M; Kabaria, Caroline W; Manh, Bui H; Elyazar, Iqbal R F; Brooker, Simon; Smith, David L; Moyeed, Rana A; Snow, Robert W

    2009-03-24

    Efficient allocation of resources to intervene against malaria requires a detailed understanding of the contemporary spatial distribution of malaria risk. It is exactly 40 y since the last global map of malaria endemicity was published. This paper describes the generation of a new world map of Plasmodium falciparum malaria endemicity for the year 2007. A total of 8,938 P. falciparum parasite rate (PfPR) surveys were identified using a variety of exhaustive search strategies. Of these, 7,953 passed strict data fidelity tests for inclusion into a global database of PfPR data, age-standardized to 2-10 y for endemicity mapping. A model-based geostatistical procedure was used to create a continuous surface of malaria endemicity within previously defined stable spatial limits of P. falciparum transmission. These procedures were implemented within a Bayesian statistical framework so that the uncertainty of these predictions could be evaluated robustly. The uncertainty was expressed as the probability of predicting correctly one of three endemicity classes; previously stratified to be an informative guide for malaria control. Population at risk estimates, adjusted for the transmission modifying effects of urbanization in Africa, were then derived with reference to human population surfaces in 2007. Of the 1.38 billion people at risk of stable P. falciparum malaria, 0.69 billion were found in Central and South East Asia (CSE Asia), 0.66 billion in Africa, Yemen, and Saudi Arabia (Africa+), and 0.04 billion in the Americas. All those exposed to stable risk in the Americas were in the lowest endemicity class (PfPR2-10 5 to or = 40%) areas. High endemicity was widespread in the Africa+ region, where 0.35 billion people are at this level of risk. Most of the rest live at intermediate risk (0.20 billion), with a smaller number (0.11 billion) at low stable risk. High levels of P. falciparum malaria endemicity are common in Africa. Uniformly low endemic levels are found in the

  18. Endangered, rare and endemic medicinal plants of the Kopetdag

    OpenAIRE

    AKMURADOV ALLAMURAD; SHAIYMOV BABAGULY; HALMEDOV BAZAR; YAKUBOV ATABEG; HALLIYEVA GULYAIYM

    2016-01-01

    The article presents some information of the place of growing of the endangered, rare and endemic medicinal plants of the Kopetdag. A monitoring has been carried out and the bioecological peculiarities, resource characteristics and modern state of the natural population of the most important species have been studied. Some scientifically based ways of protection and introduction into culture have been worked out to preserve the endangered, rare and endemic medicinal plants of the region.

  19. Endemic harvestmen and spiders of Austria (Arachnida: Opiliones, Araneae

    Directory of Open Access Journals (Sweden)

    Komposch, Christian

    2011-01-01

    Full Text Available A comprehensive overview of plant, fungus and animal species of Austria revealed a total of 748 endemic and subendemic species, including, 11 harvestman and 46 spider species. Altogether two endemic harvestmen (Nemastoma bidentatum relictum, Nemastoma schuelleri and 8 endemic spiders (Abacoproeces molestus, Collinsia (caliginosa nemenziana, Mughiphantes severus, Mughiphantes styriacus, Pelecopsis alpica, Scotophaeus nanus, Troglohyphantes novicordis, Troglohyphantes tauriscus, beside 9 subendemic harvestman and 38 subendemic spider species have been recorded from Austria. Hot-spots of endemism in the Eastern Alps are the north-eastern (Ennstaler Alps and southern Calcareous Alps (Karawanken, Karnische Alps and the Central Alps (Hohe Tauern, Gurktaler Alps, Ötztaler and Stubaier Alps. Most of the endemic arachnid species occur from the nival down to the montane zone. Important habitats are rocky areas, caves and woodlands. High absolute numbers and percentages of endemics can be found within the harvestman families Cladonychiidae, Ischyropsalididae and Nemastomatidae and in the spider genera Lepthyphantes s. l. and Troglohyphantes. The conservation status of these highly endangered taxa – 85 % of the spider species and 100 % of the harvestman taxa are endangered in Austria – is poor.

  20. NOTES ON TAXONOMY AND DISTRIBUTION OF MYRSIDEA SERINI (SÉGUY, 1944 (PHTHIRAPTERA: AMBLYCERA: MENOPONIDAE ON SOUTHERN SOUTH AMERICAN PASSERINE BIRDS (AVES: PASSERIFORMES

    Directory of Open Access Journals (Sweden)

    ARMANDO C. CICCHINO

    2015-01-01

    Full Text Available Myrsidea serini (Séguy, 1944 is recorded from three different passerine hosts from Argentina and Chile: Carduelis barbata (Molina, 1782 (Fringillidae, Chrysomus thilius petersi (Laubmann, 1934 and Agelaioides badius badius (Vieillot, 1819 (Icteridae. Somatic features and body measurements from available specimens belonging to these host-populations are compared with those recorded from Old World hosts, finding only some slight differences in certain body measurements (here interpreted as correlated to differences in host sizes, but none in chaetotaxy. This species was synoxenic with Myrsidea psittaci Carriker, 1955 on C. t. petersi in at least two localities in Buenos Aires Province, Argentina. Comparative studies of external chorionic architecture of the eggs, preferential sites of oviposition, prevalence has been carried out for both species, along with some remarks concerning the still problematic species, Myrsidea argentina (Kellogg, 1906, originally recorded off Carduelis magellanica (Vieillot, 1805.

  1. Páramo de Belmira as an important centre of endemism in the northern Colombian Andes: new evidence from Pronophilina butterflies (Lepidoptera: Nymphalidae, Satyrinae, Satyrini).

    Science.gov (United States)

    Pyrcz, Tomasz W; Clavijo, Alejandra; Uribe, Sandra; Marin, Mario A; Alvarez, Carlos F; Zubek, Anna

    2016-10-28

    Páramo de Belmira (Páramo de Santa Inés) is the highest part of the Andean Central Cordillera in the Colombian department of Antioquia. It harbours a pocket of highlands grassland vegetation isolated from the nearest southerly other large paramo extensions by some 150 km. Butterflies sampling was carried out for over three years in the cloud forest-paramo mosaic and open grassland at 2650-3350 m. As a result, several new taxa of various butterflies groups were identified, including three species and two subspecies belonging to the Satyrinae subtribe Pronophilina, described herein: Lymanopoda casneri n. sp., L. ionius lilliput n. ssp., Panyapedaliodes rojasi n. sp., Pedaliodes nutabe n. sp. and Apexacuta orsedice mariadelmarae n. ssp. L. casneri is particularly interesting from the biogeographical perspective as its nearest relative is L. hazelana Brown, found in south-central Ecuador, some 1000 km southwards. Overall, 48 species of Pronophilina were identified. Considering the occurrence of several endemic species and subspecies of butterflies in the extremely restricted paramo grasslands in the study area, and the anthropogenic pressure from surrounding locations, it is worth attributing the Páramo de Belmira a protection area status.

  2. Does migratory distance affect fuelling in a medium-distance passerine migrant?: results from direct and step-wise simulated magnetic displacements

    Directory of Open Access Journals (Sweden)

    Mihaela Ilieva

    2016-03-01

    Full Text Available In birds, fat accumulation before and during migration has been shown to be endogenously controlled and tuned by, among other factors, the Earth's magnetic field. However, our knowledge about the influence of the geomagnetic field on the fuelling in migrating birds is still limited to just a few nocturnally migrating passerine species. In order to study if variations of the magnetic field can also influence the fuelling of both day- and night-migrating passerines, we caught first-year dunnocks (Prunella modularis and subjected them to three magnetic field conditions simulated by a system of magnetic coils: (1 local geomagnetic field of southern Sweden, (2 magnetic field corresponding to the centre of the expected wintering area, and (3 magnetic field met at the northern limit of the species' breeding distribution. We did not find a difference in mass increase between the birds kept in a local magnetic field and a field resembling their wintering area, irrespectively of the mode of magnetic displacement, i.e. direct or step-wise. However, the dunnocks magnetically displaced north showed a lower rate of fuelling in comparison to the control group, probably due to elevated activity. Compared with previous studies, our results suggest that the fuelling response to magnetic displacements during the migration period is specific to the eco-physiological situation. Future studies need to address if there is an effect of magnetic field manipulation on the level of migratory activity in dunnocks and how widespread the influence of local geomagnetic field parameters is on fuelling decisions in different bird species, which have different migratory strategies, distances and migration history.

  3. Machine Learning to Assess Grassland Productivity in Southeastern Arizona

    Science.gov (United States)

    Ponce-Campos, G. E.; Heilman, P.; Armendariz, G.; Moser, E.; Archer, V.; Vaughan, R.

    2015-12-01

    We present preliminary results of machine learning (ML) techniques modeling the combined effects of climate, management, and inherent potential on productivity of grazed semi-arid grasslands in southeastern Arizona. Our goal is to support public land managers determine if agency management policies are meeting objectives and where to focus attention. Monitoring in the field is becoming more and more limited in space and time. Remotely sensed data cover the entire allotments and go back in time, but do not consider the key issue of species composition. By estimating expected vegetative production as a function of site potential and climatic inputs, management skill can be assessed through time, across individual allotments, and between allotments. Here we present the use of Random Forest (RF) as the main ML technique, in this case for the purpose of regression. Our response variable is the maximum annual NDVI, a surrogate for grassland productivity, as generated by the Google Earth Engine cloud computing platform based on Landsat 5, 7, and 8 datasets. PRISM 33-year normal precipitation (1980-2013) was resampled to the Landsat scale. In addition, the GRIDMET climate dataset was the source for the calculation of the annual SPEI (Standardized Precipitation Evapotranspiration Index), a drought index. We also included information about landscape position, aspect, streams, ponds, roads and fire disturbances as part of the modeling process. Our results show that in terms of variable importance, the 33-year normal precipitation, along with SPEI, are the most important features affecting grasslands productivity within the study area. The RF approach was compared to a linear regression model with the same variables. The linear model resulted in an r2 = 0.41, whereas RF showed a significant improvement with an r2 = 0.79. We continue refining the model by comparison with aerial photography and to include grazing intensity and infrastructure from units/allotments to assess the

  4. Land-use intensification causes multitrophic homogenization of grassland communities.

    Science.gov (United States)

    Gossner, Martin M; Lewinsohn, Thomas M; Kahl, Tiemo; Grassein, Fabrice; Boch, Steffen; Prati, Daniel; Birkhofer, Klaus; Renner, Swen C; Sikorski, Johannes; Wubet, Tesfaye; Arndt, Hartmut; Baumgartner, Vanessa; Blaser, Stefan; Blüthgen, Nico; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Jorge, Leonardo Ré; Jung, Kirsten; Keyel, Alexander C; Klein, Alexandra-Maria; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Müller, Jörg; Overmann, Jörg; Pašalić, Esther; Penone, Caterina; Perović, David J; Purschke, Oliver; Schall, Peter; Socher, Stephanie A; Sonnemann, Ilja; Tschapka, Marco; Tscharntke, Teja; Türke, Manfred; Venter, Paul Christiaan; Weiner, Christiane N; Werner, Michael; Wolters, Volkmar; Wurst, Susanne; Westphal, Catrin; Fischer, Markus; Weisser, Wolfgang W; Allan, Eric

    2016-12-08

    Land-use intensification is a major driver of biodiversity loss. Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in β-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (α)-diversity and neglected biodiversity loss at larger spatial scales. Studies addressing β-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above- and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in α-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on β-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in β-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local α-diversity in aboveground groups, whereas the α-diversity increased in belowground groups. Correlations between the β-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity

  5. Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation

    DEFF Research Database (Denmark)

    Acharya, Bharat Sharma; Rasmussen, Jim; Eriksen, Jørgen

    2012-01-01

    Grasslands are potential carbon sinks to reduce unprecedented increase in atmospheric CO2. Effect of age (1–4-year-old) and management (slurry, grazing multispecies mixture) of a grass phase mixed crop rotation on carbon sequestration and emissions upon cultivation was compared with 17-year...... biomass was highest in 4-year-old grassland, but all 1–4-year-old grasslands were in between the pea field (0.81 ± 0.094 g kg−1 soil) and the 17-year-old grassland (3.17 ± 0.22 g kg−1 soil). Grazed grasslands had significantly higher root biomass than cut grasslands. There was no significant difference...... in the CO2 emissions within 1–4-year-old grasslands. Only the 17-year-old grassland showed markedly higher CO2 emissions (4.9 ± 1.1 g CO2 kg−1 soil). Differences in aboveground and root biomass did not affect CO2 emissions, and slurry application did not either. The substantial increase in root biomass...

  6. Response of predominant soil bacteria to grassland succession as monitored by ribosomal RNA analyses

    NARCIS (Netherlands)

    Felske, A.

    1999-01-01

    The research described in this thesis was aimed to provide insight into the effects of grassland succession on the composition of the soil bacteria community in the Drentse A agricultural research area. The Drentse A meadows represent grassland succession at different stages. Since 30 years

  7. Modelling the carbon cycle of grassland in the Netherlands under various management strategies and environmental conditions.

    NARCIS (Netherlands)

    Pol-van Dasselaar, van den A.; Lantinga, E.A.

    1995-01-01

    A simulation model of the grassland carbon cycle (CCGRASS) was developed to evaluate the long-term effects of different management strategies and various environmental conditions on carbon sequestration in a loam soil under permanent grassland in the Netherlands. The model predicted that the rate of

  8. Temporal dynamics of soil nematode communities in a grassland plant diversity experiment.

    NARCIS (Netherlands)

    Viketoft, M.; Sohlenius, B.; Bostrom, S.; Palmborg, C.; Bengtsson, J.; Berg, M.P.; Kuss-Danell, K.

    2011-01-01

    We report here on an 8-year study examining links between plant and nematode communities in a grassland plant diversity experiment, located in the north of Sweden on previous agricultural soil. The examined plots contained 1, 4 and 12 common grassland plant species from three functional groups;

  9. The Impact of Ecological Construction Programs on Grassland Conservation in Inner Mongolia, China

    NARCIS (Netherlands)

    Liu, Min; Dries, Liesbeth; Heijman, Wim; Huang, Jikun; Zhu, Xueqin; Hu, Yuanning; Chen, Haibin

    2018-01-01

    A series of Ecological Construction Programs have been initiated to protect the condition of grasslands in China during recent decades. However, grassland degradation is still severe, and conditions have not been restored as intended. This paper aims to empirically examine the effectiveness of these

  10. 78 FR 19444 - Pawnee National Grassland, Colorado; Oil and Gas Leasing Analysis Environmental Impact Statement

    Science.gov (United States)

    2013-04-01

    ... Leasing Analysis on the Pawnee National Grassland (PNG), was signed. That decision determined which Lands... National Grassland. Much of the PNG's federal mineral estate made available per the 1997 ROD has already... [36 CFR 228.102(e)]. Accordingly, the PNG finds it is necessary to disclose the potential effects of...

  11. Long-term after-effects of fertilisation on restoration of calcareous grasslands

    NARCIS (Netherlands)

    Smits, N.A.C.; Bobbink, R.; Willems, J.H.

    2008-01-01

    Question: What are the long-term implications of former fertilisation for the ecological restoration of calcareous grasslands? Location: Gerendal, Limburg, The Netherlands. Methods: In 1970, ten permanent plots were established in just abandoned agricultural calcareous grassland under a regime of

  12. 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...

  13. Differentiating climate- and human-induced drivers of grassland degradation in the Liao River Basin, China.

    Science.gov (United States)

    He, Chunyang; Tian, Jie; Gao, Bin; Zhao, Yuanyuan

    2015-01-01

    Quantitatively distinguishing grassland degradation due to climatic variations from that due to human activities is of great significance to effectively governing degraded grassland and realizing sustainable utilization. The objective of this study was to differentiate these two types of drivers in the Liao River Basin during 1999-2009 using the residual trend (RESTREND) method and to evaluate the applicability of the method in semiarid and semihumid regions. The relationship between the normalized difference vegetation index (NDVI) and each climatic factor was first determined. Then, the primary driver of grassland degradation was identified by calculating the change trend of the normalized residuals between the observed and the predicted NDVI assuming that climate change was the only driver. We found that the RESTREND method can be used to quantitatively and effectively differentiate climate and human drivers of grassland degradation. We also found that the grassland degradation in the Liao River Basin was driven by both natural processes and human activities. The driving factors of grassland degradation varied greatly across the study area, which included regions having different precipitation and altitude. The degradation in the Horqin Sandy Land, with lower altitude, was driven mainly by human activities, whereas that in the Kungl Prairie, with higher altitude and lower precipitation, was caused primarily by climate change. Therefore, the drivers of degradation and local conditions should be considered in an appropriate strategy for grassland management to promote the sustainability of grasslands in the Liao River Basin.

  14. Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China

    Science.gov (United States)

    Feng-Rui Li; Zhi-Yu Zhou; Li-Ya Zhao; Ai-Sheng Zhang; Ling-Fen Kang

    2007-01-01

    This study investigated the abundance and frequency of occurrence of all shrub species present in the standing vegetation at four sites, including a 5-year exclosure (protected grassland) and three adjacent unprotected grazing sites that had been subjected to different levels of degradation (light, moderate and severe), in xeric sandy grassland of Inner Mongolia for...

  15. Variation in soil organic carbon within highland grasslands of Langtang National Park, Nepal

    Directory of Open Access Journals (Sweden)

    Keshab Shrestha

    2016-09-01

    Full Text Available Grassland also plays important role in food security. The estimated grassland area in Nepal is about 1.75 million ha. Most of the grassland in Nepal is located in higher elevation above, 2000 meter. The aim of this research is to observe difference in SOC of grassland in different altitude. Soil samples were collected from grasslands of altitude: 1500- 2000m, 2001- 2500m, 2501-3000m, 3001- 3500m and 3501- 4000m. The soil samples were collected at successive depths in each grassland i.e. 0 – 10 cm, 10 – 20 cm and 20 – 30 cm. The maximum SOC was found in grassland at altitude 3001 m- 3500m. The lowest was SOC was found in grassland at altitude 3051m – 4000m. Correlation analysis between altitude and SOC shows that SOC is positively correlated with altitude with correlation coefficient 0.850 (significant at P<0.05 level. But SOC decreases sharply in treeline with negative correlation (Significant at P<0.05.International Journal of Environment Vol.5(3 2016, pp.57-65

  16. Grassland simulation with the LPJmL model : version 3.4.018

    NARCIS (Netherlands)

    Boons-Prins, E.R.

    2010-01-01

    One third of the land surface is covered with natural and cultivated grasslands. Most of these grasslands are intensively or extensively exploited by humans to feed animals. With growing wealth, causing an increase of meat consumption, there is a need to better understand the processes that

  17. Effects of nitrogen fertilization and grazing on the emission of nitrous oxide from grassland

    Energy Technology Data Exchange (ETDEWEB)

    Velthof, G.L.; Brader, A.B.; Oenema, O. [NMI, Dept. of Soil Science and Plant Nutrition, Wageningen Agricultural Univ. (Netherlands)

    1995-11-01

    In the Netherlands, managed grasslands are potentially a large source of nitrous oxide (N{sub 2}O), because of the large nitrogen (N) input and the relatively high ground water levels. To provide insight into the major factors that contribute to N{sub 2}O emission from grassland and to provide quantitative N{sub 2}O emission rates, a monitoring study was carried out on four sites, during March 1992 to March 1994. Fluxes of N{sub 2}O increased after N fertilizer application and grazing, especially during wet conditions. Fluxes were higher from peat soils than from sand and clay soils. Fluxes were low during the winter periods. Total N{sub 2}O losses were 2 to 4.5 times higher on grassland fertilized with 160-460 kg N ha{sup -1} yr{sup -1} than on unfertilized grassland. Losses from grazed grasslands were 1.5 to 3.5 times higher than losses from mown grassland. This study shows that management practice of grassland and soil type are major factors controlling N{sub 2}O emission from grasslands. 2 figs., 3 refs.

  18. Balance matters : N:P stoichiometry and plant diversity in grassland ecosystems

    NARCIS (Netherlands)

    Fujita, Y.

    2010-01-01

    Eutrophication of Nitrogen (N) and Phosphorus (P) is threatening the functioning and biodiversity of grassland ecosystems. A well known effect of eutrophication on grasslands is an increase of above-ground productivity, which intensifies light competition and allows only a few competitive species to

  19. Spatial probability models of fire in the desert grasslands of the southwestern USA

    Science.gov (United States)

    Fire is an important driver of ecological processes in semiarid environments; however, the role of fire in desert grasslands of the Southwestern US is controversial and the regional fire distribution is largely unknown. We characterized the spatial distribution of fire in the desert grassland region...

  20. Root biomass and carbon storage in differently managed multispecies temporary grasslands

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Mortensen, Tine Bloch; Søegaard, Karen

    2012-01-01

    Species-rich grasslands may potentially increase carbon (C) storage in soil, and an experiment was established to investigate C storage in highly productive temporary multi-species grasslands. Plots were established with three mixtures: (1) a herb mixture containing salad burnet (Sanguisorba minor...

  1. Vascular plants and a brief history of the Kiowa and Rita Blanca National Grasslands

    Science.gov (United States)

    Donald L. Hazlett; Michael H. Schiebout; Paulette L. Ford

    2009-01-01

    Administered by the USDA Forest Service, the Kiowa and Rita Blanca National Grasslands occupy 230,000 acres of public land extending from northeastern New Mexico into the panhandles of Oklahoma and Texas. A mosaic of topographic features including canyons, plateaus, rolling grasslands and outcrops supports a diverse flora. Eight hundred twenty six (826) species of...

  2. Spatial patterns of grasses and shrubs in an arid grassland environment

    Science.gov (United States)

    In the Chihuahuan Desert of Mexico and New Mexico, shrub invasion is a common problem, and once-abundant grassland ecosystems are being replaced by shrub-dominated habitat. The spatial arrangement of grasses and shrubs in these arid grasslands can provide better insight into community dynamics and c...

  3. Linear objects impact on grassland degradation in the typical steppe region of China

    NARCIS (Netherlands)

    Li, Suying; Verburg, Peter H.; Lv, Shihai; Gao, Shangyu; Wu, Jingle

    2011-01-01

    Despite growing recognition of the issue of grassland degradation, few regional estimates of linear object impacts on grassland degradation [1]. We presented a methodology for evaluating regional impacts on steppe degradation from linear objects which were two uppermost types, rivers and roads, in

  4. Secondary succession after fire in Imperata grasslands of East Kalimantan Indonesia

    NARCIS (Netherlands)

    Yassir, I.; Kamp, van der J.; Buurman, P.

    2010-01-01

    Regeneration of grassland areas is becoming increasingly important, not only to create new secondary forest and recover the original biodiversity, but also recover for agriculture. We studied an early succession in Imperata grasslands in East Kalimantan, Indonesia, using plots that last burned 3

  5. Potential of endozoochorous seed dispersal by sheep in calcareous grasslands: correlations with seed traits.

    NARCIS (Netherlands)

    Kuiters, A.T.; Huiskes, H.P.J.

    2010-01-01

    Questions: What is the potential of sheep to serve as seed dispersers via ingestion and defecation in calcareous grasslands? Is the presence of viable seeds from dung correlated with specific seed traits? Location: Calcareous grasslands, South Limburg, the Netherlands/Belgium. Methods: Dung samples

  6. Hemiptera community and species responses to grassland sward islets

    OpenAIRE

    Helden, Alvin J.; Dittrich, Alex D. K.

    2016-01-01

    Sward islet is a term that has been used to describe a patch of longer vegetation in a pasture produced by a reduction in cattle grazing around their dung. They are known to affect the abundance and distribution of grassland arthropods. Hemiptera, like other groups, are found in higher densities within islets than the surrounding sward. Does this modify the community composition or is there just a density effect? Evidence from a paired (islets, non-islets) study at an Irish cattle-grazed site...

  7. Organic matter dynamics and N mineralization in grassland soils

    OpenAIRE

    Hassink, J.

    1995-01-01


    The aims of this study are i) to improve our understanding of the interactions between soil texturelsoil structure, soil organic matter, soil biota and mineralization in grassland soils, ii) to develop a procedure that yields soil organic matter fractions that can be determined directly and can be used in soil organic matter models, iii) to develop a model that predicts the long-term dynamics of soil organic matter, iv) to develop a simple model that can be used by farmers and advi...

  8. Mapping spatio-temporal variation of grassland quantity and quality using MERIS data and the PROSAIL model

    NARCIS (Netherlands)

    Si, Y.; Schlerf, M.; Zurita-Milla, R.; Skidmore, A.K.; Wang, T.

    2012-01-01

    Accurate estimates of the quantity and quality of grasslands, as they vary in space and time and from regional to global scales, furthers our understanding of grassland ecosystems. The Medium Resolution Imaging Spectrometer (MERIS) is a promising sensor for measuring and monitoring grasslands due to

  9. 78 FR 65609 - Medicine Bow-Routt National Forests and Thunder Basin National Grassland; Wyoming; Thunder Basin...

    Science.gov (United States)

    2013-11-01

    ... National Grassland; Wyoming; Thunder Basin National Grassland Prairie Dog Amendment Environmental Impact... Cooperating Agencies. No changes to the Proposed Action or Purpose of and Need for Action have been made... alternatives will be analyzed in the Thunder Basin National Grassland Prairie Dog Amendment EIS. The EIS will...

  10. Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

    Directory of Open Access Journals (Sweden)

    Lu Wen

    Full Text Available The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC, and soil total nitrogen (TN were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

  11. Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Wen, Lu; Dong, Shikui; Li, Yuanyuan; Li, Xiaoyan; Shi, Jianjun; Wang, Yanlong; Liu, Demei; Ma, Yushou

    2013-01-01

    The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe) were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

  12. Grasslands of Mexico: A perspective on their conservation (Los pastizales del norte de Mexico: Una perspectiva para su conservacion)

    Science.gov (United States)

    Patricia Manzano; Rurik List

    2006-01-01

    Grasslands are areas dominated by grasses and herbs with few or no trees. Grasslands receive too much rain for a desert environment and too little for a forest. Temperate North American grasslands, especially, have undergone changes on a continental level. Their high productivity and fertility, added to their level topography and lack of trees, make them ideal sites...

  13. FOLIAR ANATOMY OF ENDEMICS SPECIES OF Cattleya (ORCHIDACEAE ENDEMIC FROM GUIANA SHIELD

    Directory of Open Access Journals (Sweden)

    Graciene Tomaz Carneiro

    2017-03-01

    Full Text Available The main goal of this study was characterize the leaf's anatomical aspects of Cattleya jenmanii Rolfe and e C. lawrenceana Rchb. f., describing its anatomical structures in order to increase the knowledge of this endemic species from the region of the Guiana Shield. Besides, it also intended to identify foliar characters to assist in the anatomical comparison of these species. For anatomical study, the material was fixed in FAA and to make the slides we used the usual cut freehand technique and stained with double staining from Safranin with Blue Astra (Safrablau. C. jenmanii and C. lawrenceana has fleshy leaves covered with a thick cuticle. The mesophyll presented dorsiventral with collateral vascular bundles. A large number of bundles of smaller caliber fibers are distributed in the mesophyll poles. Only the presence of a subepidermal layer of fibers differed C. lawrenceana from C. jenmanii. Keyword: Roraima; Guiana Shield; Cattleya; Amazon Basin.

  14. Future productivity and phenology changes in European grasslands for different warming levels: implications for grassland management and carbon balance

    OpenAIRE

    Chang, Jinfeng; Ciais, Philippe; Viovy, Nicolas; Soussana, Jean-Fran?ois; Klumpp, Katja; Sultan, Benjamin

    2017-01-01

    Background Europe has warmed more than the global average (land and ocean) since pre-industrial times, and is also projected to continue to warm faster than the global average in the twenty-first century. According to the climate models ensemble projections for various climate scenarios, annual mean temperature of Europe for 2071?2100 is predicted to be 1?5.5??C higher than that for 1971?2000. Climate change and elevated CO2 concentration are anticipated to affect grassland management and liv...

  15. Nitrogen acquisition by plants and microorganisms in a temperate grassland.

    Science.gov (United States)

    Liu, Qianyuan; Qiao, Na; Xu, Xingliang; Xin, Xiaoping; Han, Jessie Yc; Tian, Yuqiang; Ouyang, Hua; Kuzyakov, Yakov

    2016-03-10

    Nitrogen (N) limitation is common in most terrestrial ecosystems, often leading to strong competition between microorganisms and plants. The mechanisms of niche differentiation to reduce this competition remain unclear. Short-term (15)N experiments with NH4(+), NO3(-), and glycine were conducted in July, August and September in a temperate grassland to evaluate the chemical, spatial and temporal niche differentiation by competition between plants and microorganisms for N. Microorganisms preferred NH4(+) and NO3(-), while plants preferred NO3(-). Both plants and microorganisms acquired more N in August and September than in July. The soil depth had no significant effects on microbial uptake, but significantly affected plant N uptake. Plants acquired 67% of their N from the 0-5 cm soil layer and 33% from the 5-15 cm layer. The amount of N taken up by microorganisms was at least seven times than plants. Although microorganisms efficiently compete for N with plants, the competition is alleviated through chemical partitioning mainly in deeper soil layer. In the upper soil layer, neither chemical nor temporal niche separation is realized leading to strong competition between plants and microorganisms that modifies N dynamics in grasslands.

  16. 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.

  17. Weathering controls on mechanisms of carbon storage in grassland soils

    Science.gov (United States)

    Masiello, C.A.; Chadwick, O.A.; Southon, J.; Torn, M.S.; Harden, J.W.

    2004-01-01

    On a sequence of soils developed under similar vegetation, temperature, and precipitation conditions, but with variations in mineralogical properties, we use organic carbon and 14C inventories to examine mineral protection of soil organic carbon. In these soils, 14C data indicate that the creation of slow-cycling carbon can be modeled as occurring through reaction of organic ligands with Al3+ and Fe3+ cations in the upper horizons, followed by sorption to amorphous inorganic Al compounds at depth. Only one of these processes, the chelation Al3+ and Fe3+ by organic ligands, is linked to large carbon stocks. Organic ligands stabilized by this process traverse the soil column as dissolved organic carbon (both from surface horizons and root exudates). At our moist grassland site, this chelation and transport process is very strongly correlated with the storage and long-term stabilization of soil organic carbon. Our 14C results show that the mechanisms of organic carbon transport and storage at this site follow a classic model previously believed to only be significant in a single soil order (Spodosols), and closely related to the presence of forests. The presence of this process in the grassland Alfisol, Inceptisol, and Mollisol soils of this chronosequence suggests that this process is a more significant control on organic carbon storage than previously thought. Copyright 2004 by the American Geophysical Union.

  18. The endemic plants of Micronesia: a geographical checklist and commentary

    Directory of Open Access Journals (Sweden)

    Lorence, D.H.

    2012-05-01

    Full Text Available The Micronesia-Polynesia bioregion is recognized as a global biodiversity hotspot. However, until now estimates regarding the number of endemic plant species for the region were not supported by any comprehensive published work for the region. The results of this study indicate that Micronesia has the world’s highest percentage of plant endemism per square kilometer out of all globally recognized insular biodiversity hotspots. A checklist of all endemic plant species for Micronesia is presented here with their corresponding geographical limits within the region. A summary of previous work and estimates is also provided noting the degree of taxonomic progress in the past several decades. A total of 364 vascular plant species are considered endemic to Micronesia, most of them being restricted to the Caroline Islands with a large percentage restricted to Palau. The checklist includes seven new combinations, one new name, and two unverified names that require additional study to verify endemic status. Overviews of each respective botanical family represented in the list are given including additional information on the Micronesian taxa. Recommendations for future work and potential projects are alluded to throughout the text highlighting major data gaps and very poorly known taxa. The following new combinations and names are made: Cyclosorus carolinensis (Hosokawa Lorence, comb. nov. , Cyclosorusgretheri (W. H. Wagner Lorence, comb. nov., Cyclosorusguamensis (Holttum Lorence, comb. nov., Cyclosorus palauensis (Hosokawa Lorence, comb. nov. , Cyclosorus rupiinsularis (Fosberg Lorence, comb. nov., Dalbergia hosokawae (Hosokawa Costion nom. nov., Syzygium trukensis (Hosokawa Costion & E. Lucas comb. nov.

  19. A checklist of the plants of the forests and grasslands in the Weza district, southern KwaZulu-Natal and a review of their status in the Red Data List

    Directory of Open Access Journals (Sweden)

    Graham R.H. Grieve

    2015-09-01

    Full Text Available Eastern mistbelt forests are naturally fragmented forests with grassland which occur from the Eastern Cape to KwaZulu-Natal, South Africa. These were heavily logged by colonial settlers and continue to be harvested despite being protected. Consequently we documented a checklist of the plants of the forests and grasslands in the Weza district (3029DA WEZA, southern KwaZulu-Natal, including Ngeli Forest and nearby indigenous forest patches to highlight their biodiversity status and need for conservation. We also reviewed their status in the Red Data List. Of the 1554 records included in this summary of plant species for the Weza district, there were 6 lichens (0.4%, 46 bryophytes (3.0%, 58 pteridophytes (3.7%, 6 gymnosperms (0.4% and the remaining 1424 species angiosperms (92.5%. Of the angiosperms, 27.3% were monocotyledons and 72.7% were dicotyledons. The most species-rich family was Asteraceae (239 species followed by Fabaceae (115 species, Liliaceae (used for purposes of comparison against older studies – 89 species, Orchidaceae (89 species, Iridaceae (59 species, Poaceae (58 species, Asclepidaceae (again used for purposes of comparison against older studies – 57 species, Scrophulariaceae (42 species, Euphorbiaceae (32 species, Lamiaceae (32 species and Rubiaceae (27 species. These 10 families each comprised more than 2% of the species in the list. Together they contributed 55% of the angiosperm species and 34.1% of the angiosperm genera. The biodiversity and conservation value of the study area are conserved pockets of eastern mistbelt forest, Drakensberg foothill moist grassland and mistbelt grassland. More than 4% of the species are under some degree of threat, as was evidenced by the number of species regarded as endangered (5, vulnerable (18, near threatened (10, critically rare (1, rare (20 or declining (11 amongst the 1554 species covered in the list. Conservation implications: In terms of taxa under some degree of threat, number of

  20. Understanding of Grassland Ecosystems under Climate Change and Economic Development Pressures in the Mongolia Plateau

    Science.gov (United States)

    Qi, J.; Chen, J.; Shan, P.; Pan, X.; Wei, Y.; Wang, M.; Xin, X.

    2011-12-01

    The land use and land cover change, especially in the form of grassland degradation, in the Mongolian Plateau, exhibited a unique spatio-temporal pattern that is a characteristic of a mixed stress from economic development and climate change of the region. The social dimension of the region played a key role in shaping the landscape and land use change, including the cultural clashes with economic development, conflicts between indigenous people and business ventures, and exogenous international influences. Various research projects have been conducted in the region to focus on physical degradation of grasslands and/or on economic development but there is a lack of understanding how the social and economic dimensions interact with grassland ecosystems and changes. In this talk, a synthesis report was made based on the most recent workshop held in Hohhot, Inner Mongolia, of China, that specifically focused on climate change and grassland ecosystems. The report analyzed the degree of grassland degradation, its climate and social drivers, and coupling nature of economic development and conservation of traditional grassland values. The goal is to fully understand the socio-ecological-economic interactions that together shape the trajectory of the grassland ecosystems in the Mongolia Plateau.

  1. Impact of Climate Change on Temperate and Alpine Grasslands in China during 1982–2006

    Directory of Open Access Journals (Sweden)

    Xiangjin Shen

    2015-01-01

    Full Text Available Based on GIMMS NDVI and climate data from 1982 to 2006, this study analyzed the impact of climate change on grassland in China. During the growing season, there were significant effects of precipitation on the growth of all the grassland types (P<0.05, except for meadow vegetation. For the air temperatures, there existed asymmetrical effects of maximum temperature (Tmax and minimum temperature (Tmin on grassland vegetation, especially for the temperate grasslands and alpine steppe. The growing season NDVI correlated negatively with Tmax but positively with Tmin for temperate grasslands. Seasonally, these opposite effects were only observed in summer. For alpine steppe, the growing season NDVI correlated positively with Tmax but negatively with Tmin, and this pattern of asymmetrical responses was only obvious in spring and autumn. Under the background of global asymmetric warming, more attention should be paid to this asymmetric response of grassland vegetation to daytime and night-time warming, especially when we want to predict the productivity of China’s grasslands in the future.

  2. Are Agrofuels a conservation threat or opportunity for grassland birds in the United States?

    Science.gov (United States)

    Robertson, Bruce A.; Rice, Robert A.; Ribic, Christine; Babcock, Bruce A.; Landis, Douglas A.; Herkert, James R.; Fletcher, Robert J.; Fontaine, Joseph J; Doran, Patrick J.; Schemske, Douglas W.

    2012-01-01

    In the United States, government-mandated growth in the production of crops dedicated to biofuel (agrofuels) is predicted to increase the demands on existing agricultural lands, potentially threatening the persistence of populations of grassland birds they support. We review recently published literature and datasets to (1) examine the ability of alternative agrofuel crops and their management regimes to provide habitat for grassland birds, (2) determine how crop placement in agricultural landscapes and agrofuel-related land-use change will affect grassland birds, and (3) identify critical research and policy-development needs associated with agrofuel production. We find that native perennial plants proposed as feedstock for agrofuel (switchgrass, Panicum virgatum, and mixed grass—forb prairie) have considerable potential to provide new habitat to a wide range of grassland birds, including rare and threatened species. However, industrialization of agrofuel production that maximizes biomass, homogenizes vegetation structure, and results in the cultivation of small fields within largely forested landscapes is likely to reduce species richness and/or abundance of grassland-dependent birds. Realizing the potential benefits of agrofuel production for grassland birds' conservation will require the development of new policies that encourage agricultural practices specifically targeting the needs of grassland specialists. The broad array of grower-incentive programs in existence may deliver new agrofuel policies effectively but will require coordination at a spatial scale broader than currently practiced, preferably within an adaptive-management framework.

  3. 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.

  4. [Community structure and diversity of soil arthropods in naturally restored sandy grasslands after grazing].

    Science.gov (United States)

    Liu, Ren-tao; Zhao, Ha-lin; Zhao, Xue-yong

    2010-11-01

    Taking the Naiman Desertification Research Station under Chinese Academy of Sciences as a base, an investigation was conducted on the community structure of soil arthropods in the naturally restored sandy grasslands after different intensity grazing disturbance, with the effects of vegetation and soil on this community structure approached. In the non-grazing grassland, soil arthropods were rich in species and more in individuals, and had the highest diversity. In the restored grassland after light grazing, soil arthropods had the lowest evenness and diversity. In the restored grassland after moderate grazing, the individuals of soil arthropods were lesser but the major groups were more, and the evenness and diversity were higher. In the restored grassland after heavy grazing, the individuals of soil arthropods were more but the major groups were lesser, and the diversity was higher. Plant individuals' number, vegetation height and coverage, and soil alkalinity were the main factors affecting the soil arthropod community in naturally restored grasslands after different intensity grazing disturbance. It was implied that after 12-year exclosure of grassland, soil arthropod community could be recovered to some degree, while grazing disturbance had long-term negative effects on the arthropod community.

  5. Grasslands and Croplands Have Different Microbial Biomass Carbon Levels per Unit of Soil Organic Carbon

    Directory of Open Access Journals (Sweden)

    Terence P. McGonigle

    2017-07-01

    Full Text Available Primarily using cropped systems, previous studies have reported a positive linear relationship between microbial biomass carbon (MBC and soil organic carbon (SOC. We conducted a meta-analysis to explore this relationship separately for grasslands and croplands using available literature. Studies were limited to those using fumigation–extraction for MBC for field samples. Trials were noted separately where records were distinct in space or time. Grasslands were naturally occurring, restored, or seeded. Cropping systems were typical of the temperate zone. MBC had a positive linear response to increasing SOC that was significant in both grasslands (p < 0.001; r2 = 0.76 and croplands (p < 0.001; r2 = 0.48. However, MBC increased 2.5-fold more steeply per unit of increasing SOC for grassland soils, as compared to the corresponding response in cropland soils. Expressing MBC as a proportion of SOC across the regression overall, slopes corresponded to 2.7% for grasslands and 1.1% for croplands. The slope of the linear relationship for grasslands was significantly (p = 0.0013 steeper than for croplands. The difference between the two systems is possibly caused by a greater proportion of SOC in grasslands being active rather than passive, relative to that in croplands, with that active fraction promoting the formation of MBC.

  6. Elevational plant species richness patterns and their drivers across non-endemics, endemics and growth forms in the Eastern Himalaya.

    Science.gov (United States)

    Manish, Kumar; Pandit, Maharaj K; Telwala, Yasmeen; Nautiyal, Dinesh C; Koh, Lian Pin; Tiwari, Sudha

    2017-09-01

    Despite decades of research, ecologists continue to debate how spatial patterns of species richness arise across elevational gradients on the Earth. The equivocal results of these studies could emanate from variations in study design, sampling effort and data analysis. In this study, we demonstrate that the richness patterns of 2,781 (2,197 non-endemic and 584 endemic) angiosperm species along an elevational gradient of 300-5,300 m in the Eastern Himalaya are hump-shaped, spatial scale of extent (the proportion of elevational gradient studied) dependent and growth form specific. Endemics peaked at higher elevations than non-endemics across all growth forms (trees, shrubs, climbers, and herbs). Richness patterns were influenced by the proportional representation of the largest physiognomic group (herbs). We show that with increasing spatial scale of extent, the richness patterns change from a monotonic to a hump-shaped pattern and richness maxima shift toward higher elevations across all growth forms. Our investigations revealed that the combination of ambient energy (air temperature, solar radiation, and potential evapo-transpiration) and water availability (soil water content and precipitation) were the main drivers of elevational plant species richness patterns in the Himalaya. This study highlights the importance of factoring in endemism, growth forms, and spatial scale when investigating elevational gradients of plant species distributions and advances our understanding of how macroecological patterns arise.

  7. Assessing the biophysical naturalness of grassland in eastern North Dakota with hyperspectral imagery

    Science.gov (United States)

    Zhou, Qiang

    Over the past two decades, non-native species within grassland communities have quickly developed due to human migration and commerce. Invasive species like Smooth Brome grass (Bromus inermis) and Kentucky Blue Grass (Poa pratensis), seriously threaten conservation of native grasslands. This study aims to discriminate between native grasslands and planted hayfields and conservation areas dominated by introduced grasses using hyperspectral imagery. Hyperspectral imageries from the Hyperion sensor on EO-1 were acquired in late spring and late summer on 2009 and 2010. Field spectra for widely distributed species as well as smooth brome grass and Kentucky blue grass were collected from the study sites throughout the growing season. Imagery was processed with an unmixing algorithm to estimate fractional cover of green and dry vegetation and bare soil. As the spectrum is significantly different through growing season, spectral libraries for the most common species are then built for both the early growing season and late growing season. After testing multiple methods, the Adaptive Coherence Estimator (ACE) was used for spectral matching analysis between the imagery and spectral libraries. Due in part to spectral similarity among key species, the results of spectral matching analysis were not definitive. Additional indexes, "Level of Dominance" and "Band variance", were calculated to measure the predominance of spectral signatures in any area. A Texture co-occurrence analysis was also performed on both "Level of Dominance" and "Band variance" indexes to extract spatial characteristics. The results suggest that compared with disturbed area, native prairie tend to have generally lower "Level of Dominance" and "Band variance" as well as lower spatial dissimilarity. A final decision tree model was created to predict presence of native or introduced grassland. The model was more effective for identification of Mixed Native Grassland than for grassland dominated by a single

  8. 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.

  9. Effects of 10-Year Management Regimes on the Soil Seed Bank in Saline-Alkaline Grassland

    Science.gov (United States)

    Ma, Hongyuan; Yang, Haoyu; Liang, Zhengwei; Ooi, Mark K. J.

    2015-01-01

    Background Management regimes for vegetation restoration of degraded grasslands can significantly affect the process of ecological succession. However, few studies have focused on variation in the soil seed bank during vegetation restoration under different management regimes, especially in saline-alkaline grassland habitats. Our aim was to provide insights into the ecological effects of grassland management regimes on soil seed bank composition and vegetation establishment in mown, fenced, transplanted and natural grassland sites, all dominated by the perennial rhizomatous grass Leymus chinensis. Methodology We studied species composition and diversity in both the soil seed bank and aboveground vegetation in differently managed grasslands in Northeast China. An NMDS (nonmetric multidimensional scaling) was used to evaluate the relationship between species composition, soil seed banks, aboveground vegetation and soil properties. Principal Findings Fenced and mown grassland sites had high density and species richness in both the soil seed bank and aboveground vegetation. The Transplanted treatment exhibited the highest vegetation growth and seed production of the target species L. chinensis. Seeds of L. chinensis in the soil occurred only in transplanted and natural grassland. Based on the NMDS analysis, the number of species in both the soil seed bank and aboveground vegetation were significantly related to soil Na+, Cl-, RSC (residual sodium carbonate), alkalinity, ESP (exchangeable sodium percentage) and AP (available phosphorus). Conclusions Soil seed bank composition and diversity in the saline-alkaline grassland were significantly affected by the management regimes implemented, and were also significantly related to the aboveground vegetation and several soil properties. Based on vegetative growth, reproductive output and maintenance of soil seed bank, the transplanting was identified as the most effective method for relatively rapid restoration of the target

  10. Traditional cattle grazing in a mosaic alkali landscape: effects on grassland biodiversity along a moisture gradient.

    Directory of Open Access Journals (Sweden)

    Péter Török

    Full Text Available Extensively managed pastures are of crucial importance in sustaining biodiversity both in local- and landscape-level. Thus, re-introduction of traditional grazing management is a crucial issue in grassland conservation actions worldwide. Traditional grazing with robust cattle breeds in low stocking rates is considered to be especially useful to mimic natural grazing regimes, but well documented case-studies are surprisingly rare on this topic. Our goal was to evaluate the effectiveness of traditional Hungarian Grey cattle grazing as a conservation action in a mosaic alkali landscape. We asked the following questions: (i How does cattle grazing affect species composition and diversity of the grasslands? (ii What are the effects of grazing on short-lived and perennial noxious species? (iii Are there distinct effects of grazing in dry-, mesophilous- and wet grassland types? Vegetation of fenced and grazed plots in a 200-ha sized habitat complex (secondary dry grasslands and pristine mesophilous- and wet alkali grasslands was sampled from 2006-2009 in East-Hungary. We found higher diversity scores in grazed plots compared to fenced ones in mesophilous- and wet grasslands. Higher cover of noxious species was typical in fenced plots compared to their grazed counterparts in the last year in every studied grassland type. We found an increasing effect of grazing from the dry- towards the wet grassland types. The year-to-year differences also followed similar pattern: the site-dependent effects were the lowest in the dry grassland and an increasing effect was detected along the moisture gradient. We found that extensive Hungarian Grey cattle grazing is an effective tool to suppress noxious species and to create a mosaic vegetation structure, which enables to maintain high species richness in the landscape. Hungarian Grey cattle can feed in open habitats along long moisture gradient, thus in highly mosaic landscapes this breed can be the most suitable

  11. Endemic pemphigus foliaceus in Venezuela: report of two children.

    Science.gov (United States)

    González, Francisco; Sáenz, Ana Maria; Cirocco, Antonietta; Tacaronte, Inés Maria; Fajardo, Javier Enrique; Calebotta, Adriana

    2006-01-01

    Two native Yanomami children from the Venezuelan Amazonia with erythroderma were hospitalized on our service. Clinical, histologic, and immunofluorescence studies diagnosed endemic pemphigus foliaceous. Human leukocyte antigen class II showed DRB1*04 subtype *0411, which has not been previously associated with this disease. However, it shares a common epitope with all the human leukocyte antigen DRB1 alleles that have been involved in this disease among Brazilian populations. Although this condition is endemic in Brazil, our patients are the first two reported in Venezuela.

  12. Recent trends, drivers, and projections of carbon cycle processes in forests and grasslands of North America

    Science.gov (United States)

    Domke, G. M.; Williams, C. A.; Birdsey, R.; Pendall, E.

    2017-12-01

    In North America forest and grassland ecosystems play a major role in the carbon cycle. Here we present the latest trends and projections of United States and North American carbon cycle processes, stocks, and flows in the context of interactions with global scale budgets and climate change impacts in managed and unmanaged grassland and forest ecosystems. We describe recent trends in natural and anthropogenic disturbances in these ecosystems as well as the carbon dynamics associated with land use and land cover change. We also highlight carbon management science and tools for informing decisions and opportunities for improving carbon measurements, observations, and projections in forests and grasslands.

  13. Quantifying the pedo-ecohydrological structure and function of degraded, grassland ecosystems

    Science.gov (United States)

    Brazier, Richard E.

    2015-04-01

    Grassland ecosystems cover significant areas of the terrestrial land mass, across a range of geoclimates, from arctic tundra, through temperate and semi-arid landscapes. In very few locations, such grasslands may be termed 'pristine' in that they remain undamaged by human activities and resilient to changing climates. In far more cases, grasslands are being degraded, often irreversibly so, with significant implications for a number of ecosystem services related to water resources, soil quality, nutrient cycles, and therefore both global food and water security. This paper draws upon empirical research that has been undertaken over the last decade to characterise a range of different grasslands in terms of soil properties, vegetation structure and geomorphology and to understand how these structures or patterns might interact or control how the grassland ecosystems function. Particular emphasis is placed upon quantifying fluxes of water, within and from grasslands, but also fluxes of sediment, via the processes of soil erosion and finally fluxes of the macronutrients Nitrogen, Phosphorus and Carbon from the landscape to surface waters. Data are presented from semi-arid grasslands, which are subject to severe encroachment by woody species, temperate upland grasslands that have been 'improved' via drainage to support grazing, temperate lowland grasslands, that are unimproved (Culm or Rhôs pastures) and finally intensively managed grasslands in temperate regions, that have been significantly modified via land management practices to improve productivity. It is hypothesised that, once degraded, the structure and function of these very diverse grassland ecosystems follows the same negative trajectory, resulting in depleted soil depths, nutrient storage capacities and therefore reduced plant growth and long-term carbon sequestration. Results demonstrate that similar, but highly complex and non-linear responses to perturbation of the ecosystem are observed, regardless of

  14. Effects of management practices on grassland birds: Grasshopper Sparrow

    Science.gov (United States)

    Dechant, Jill A.; Sondreal, Marriah L.; Johnson, Douglas H.; Igl, Lawrence D.; Goldade, Christopher M.; Nenneman, Melvin P.; Euliss, Betty R.

    1998-01-01

    Information on the habitat requirements and effects of habitat management on grassland birds were summarized from information in more than 5,500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although birds frequently are observed outside the breeding range indicated, the maps are intended to show areas where managers might concentrate their attention. It may be ineffectual to manage habitat at a site for a species that rarely occurs in an area. The species account begins with a brief capsule statement, which provides the fundamental components or keys to management for the species. A section on breeding range outlines the current breeding distribution of the species in North America, including areas that could not be mapped using BBS data. The suitable habitat section describes the breeding habitat and occasionally microhabitat characteristics of the species, especially those habitats that occur in the Great Plains. Details on habitat and microhabitat requirements often provide clues to how a species will respond to a particular management practice. A table near the end of the account complements the section on suitable habitat, and lists the specific habitat characteristics for the species by individual studies. A special section on prey habitat is included for those predatory species that have more specific prey requirements. The area requirements section provides details on territory and home range sizes, minimum area requirements, and the effects of patch size, edges, and other landscape and habitat features on abundance and productivity. It may be futile to manage a small block of suitable habitat for a species that has minimum area requirements that are larger than the area being managed. The Brown-headed Cowbird (Molothrus ater) is an obligate brood parasite of many grassland birds. The section on cowbird brood parasitism summarizes rates

  15. Monitoring soil greenhouse gas emissions from managed grasslands

    Science.gov (United States)

    Díaz-Pinés, Eugenio; Lu, Haiyan; Butterbach-Bahl, Klaus; Kiese, Ralf

    2014-05-01

    Grasslands in Central Europe are of enormous social, ecological and economical importance. They are intensively managed, but the influence of different common practices (i.e. fertilization, harvesting) on the total greenhouse gas budget of grasslands is not fully understood, yet. In addition, it is unknown how these ecosystems will react due to climate change. Increasing temperatures and changing precipitation will likely have an effect on productivity of grasslands and on bio-geo-chemical processes responsible for emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). In the frame of the TERENO Project (www.tereno.net), a long-term observatory has been implemented in the Ammer catchment, southern Germany. Acting as an in situ global change experiment, 36 big lysimeters (1 m2 section, 150 cm height) have been translocated along an altitudinal gradient, including three sites ranging from 600 to 860 meters above sea level. In addition, two treatments have been considered, corresponding to different management intensities. The overall aim of the pre-alpine TERENO observatory is improving our understanding of the consequences of climate change and management on productivity, greenhouse gas balance, soil nutritional status, nutrient leaching and hydrology of grasslands. Two of the sites are equipped with a fully automated measurement system in order to continuously and accurately monitor the soil-atmosphere greenhouse gas exchange. Thus, a stainless steel chamber (1 m2 section, 80 cm height) is controlled by a robotized system. The chamber is hanging on a metal structure which can move both vertically and horizontally, so that the chamber is able to be set onto each of the lysimeters placed on the field. Furthermore, the headspace of the chamber is connected with a gas tube to a Quantum Cascade Laser, which continuously measures CO2, CH4, N2O and H2O mixing ratios. The chamber acts as a static chamber and sets for 15 minutes onto each lysimeter

  16. Transient behavior of cadmium in a grassland arthropod food chain

    International Nuclear Information System (INIS)

    Van Hook, R.I.; Yates, A.J.

    1975-01-01

    Biological assimilation and transport of cadmium were determined for an arthropod food chain in an east Tennessee grassland community. Laboratory experiments demonstrated that there were no significant differences (P greater than 0.05) in assimilation rates (17 percent assimilation per day) or biological half-lives (7 days) of 109 Cd either as soluble nitrate or insoluble oxide in crickets under identical conditions. Field experiments demonstrated that primary consumers (crickets) accumulated 109 Cd much more rapidly (uptake rate = 0.55 day -1 ) than did the spider predators (uptake rate = 0.08 day -1 ). Equilibrium concentrations in crickets were obtained in 9 days (0.04 ppM cadmium), while equilibrium was not reached in spiders during the 30-day study. Food-chain concentration of cadmium did not occur as crickets accumulated levels of cadmium 60 percent of that in their vegetation food sources and spiders accumulated only 70 percent of the cadmium present in the cricket tissues

  17. Experimental control of Spanish broom (Spartium junceum invading natural grasslands

    Directory of Open Access Journals (Sweden)

    Cristina Sanhueza

    2012-12-01

    Full Text Available A group of legumes generically known as brooms are among the most successful shrubs invading grasslands in South America and otherregions. These species share a set of biological features that enhance their invasiveness, such as abundant and long-lasting seed banks,aggressive root systems and rapid growth, combined with their ability for re-sprouting after cutting or burning and for avoiding herbivores.They grow in dense stands that exclude native vegetation and are able to change ecological processes, increasing fire frequency and intensity,and fixing atmospheric nitrogen. The Spanish broom (Spartium junceum is a shrub native form the Mediterranean that was introduced intothe Argentine Pampas grasslands where it spreads over remnants of pristine ecosystems, threatening their biodiversity. This paper reports theresults obtained after an adaptive management strategy aimed at controlling this species in a nature reserve, and compares the efficiency ofdifferent mechanical and chemical control techniques in terms of the number of plants killed and the effects on surrounding vegetation andon the recruitment of broom seedlings. Control was implemented in two phases, the first included three treatments: i cut at the base of theplant, ii cut followed by the immediate application of Togar (Picloram 3% + Triclopyr 6%, at a 5% dilution in diesel oil on top of the cut stump, and iii foliar spraying with Togar. The follow-up treatments, implemented one year later, consisted of spraying the re-sprouts with Togar (5% in diesel oil or Glyphosate 36% (2% in water. The best option in terms of controlling Spanish broom was spraying the resprouts with Togar which gave 100% mortality of the treated plants, compared with values of 40% - 100% re-sprouting for the other optionstested. None of the methods was associated with an increase in seedling recruitment, nor with significant changes in the vegetation in the immediate vicinity of the controlled brooms.

  18. Surface temperature retrieval in a temperate grassland with multiresolution sensors

    Science.gov (United States)

    Goetz, S. J.; Halthore, R. N.; Hall, F. G.; Markham, B. L.

    1995-12-01

    Radiometric surface temperatures retrieved at various spatial resolutions from aircraft and satellite measurements at the FIFE site in eastern Kansas were compared with near-surface temperature measurements to determine the accuracy of the retrieval techniques and consistency between the various sensors. Atmospheric characterizations based on local radiosonde profiles of temperature, pressure, and water vapor were used with the LOWTRAN-7 and MODTRAN atmospheric radiance models to correct measured thermal radiances of water and grassland targets for atmospheric attenuation. Comparison of retrieved surface temperatures from a helicopter-mounted modular multispectral radiometer (MMR) (˜5-m "pixel"), C-130 mounted thematic mapper simulator (TMS) (NS001, ˜20-m pixel), and the Landsat 5 thematic mapper (TM) (120-m pixel) was done. Differences between atmospherically corrected radiative temperatures and near-surface measurements ranged from less than 1°C to more than 8°C. Corrected temperatures from helicopter-MMR and NS001-TMS were in general agreement with near-surface infrared radiative thermometer (IRT) measurements collected from automated meteorological stations, with mean differences of 3.2°C and 1.7°C for grassland targets. Much better agreement (within 1°C) was found between the retrieved aircraft surface temperatures and near-surface measurements acquired with a hand-held mast equipped with a MMR and IRT. The NS001-TMS was also in good agreement with near-surface temperatures acquired over water targets. In contrast, the Landsat 5 TM systematically overestimated surface temperature in all cases. This result has been noted previously but not consistently. On the basis of the results reported here, surface measurements were used to provide a calibration of the TM thermal channel. Further evaluation of the in-flight radiometric calibration of the TM thermal channel is recommended.

  19. Modelling nitrous oxide emissions from grazed grassland systems

    International Nuclear Information System (INIS)

    Wang Junye; Cardenas, Laura M.; Misselbrook, Tom H.; Cuttle, Steve; Thorman, Rachel E.; Li Changsheng

    2012-01-01

    Grazed grassland systems are an important component of the global carbon cycle and also influence global climate change through their emissions of nitrous oxide and methane. However, there are huge uncertainties and challenges in the development and parameterisation of process-based models for grazed grassland systems because of the wide diversity of vegetation and impacts of grazing animals. A process-based biogeochemistry model, DeNitrification-DeComposition (DNDC), has been modified to describe N 2 O emissions for the UK from regional conditions. This paper reports a new development of UK-DNDC in which the animal grazing practices were modified to track their contributions to the soil nitrogen (N) biogeochemistry. The new version of UK-DNDC was tested against datasets of N 2 O fluxes measured at three contrasting field sites. The results showed that the responses of the model to changes in grazing parameters were generally in agreement with observations, showing that N 2 O emissions increased as the grazing intensity increased. - Highlights: ► Parameterisation of grazing system using grazing intensity. ► Modification of UK D NDC for the UK soil and weather conditions. ► Validation of the UK D NDC against measured data of N 2 O emissions in three UK sites. ► Estimating influence of animal grazing practises on N 2 O emissions. - Grazing system was parameterised using grazing intensity and UK-DNDC model was modified and validated against measured data of N 2 O emissions in three UK sites.

  20. Grassland communities of traditional orchards in the Western Carpathians (Slovakia

    Directory of Open Access Journals (Sweden)

    Hubert Zarnovican

    2017-06-01

    Full Text Available Traditional orchards are a valuable feature of the rural landscape and they are specific for regions with scattered settlement such as the Myjava hilly land and White Carpathians. Here, the permanent species-rich grasslands beneath trees were regularly managed in the traditional manner until some were replaced in the 1970’s and 80’s by intensively managed orchards, some of which were abandoned in the early 1990’s. Our 2011–2015 phytosociological research followed the standard Braun-Blanquet approach. We classified 178 phytosociological relevés recorded in orchard meadows (156 relevés, former intensively managed orchards (16 relevés, and two relevés from a semi-intensively grazed orchard. Traditionally managed orchard meadows were classified in the following five units: (i Pastinaco sativae-Arrhenatheretum elatioris – thermophilous variant, (ii Pastinaco sativae-Arrhenatheretum elatioris – transitional variant to Alchemillo-Arrhenatheretum elatioris, (iii Ranunculo bulbosi-Arrhenatheretum elatioris, (iv Onobrychido viciifoliae-Brometum erecti, and (v Brachypodio pinnati-Molinietum arundinaceae. Formerly intensively managed large-scale orchards were classified as Pastinaco sativae-Arrhenatheretum elatioris association and the semi-intensively grazed orchard as Lolio perennis-Cynosuretum cristati association. The species composition varies considerably due to tree-shading and different management treatments applied in the orchards, so the relevés of the delimited syntaxonomic units are not typical and have transitional character. Moisture, soil nutrients, and soil reaction were identified as the main environmental gradients influencing species composition. We tested four management treatments in direct gradient analysis and found that abandonment has the strongest effect on species composition. Comparison of grassland vegetation in the studied traditional orchards with that described in Germany reveals differences in species

  1. Grassland invader responses to realistic changes in native species richness.

    Science.gov (United States)

    Rinella, Matthew J; Pokorny, Monica L; Rekaya, Romdhane

    2007-09-01

    The importance of species richness for repelling exotic plant invasions varies from ecosystem to ecosystem. Thus, in order to prioritize conservation objectives, it is critical to identify those ecosystems where decreasing richness will most greatly magnify invasion risks. Our goal was to determine if invasion risks greatly increase in response to common reductions in grassland species richness. We imposed treatments that mimic management-induced reductions in grassland species richness (i.e., removal of shallow- and/or deep-rooted forbs and/or grasses and/or cryptogam layers). Then we introduced and monitored the performance of a notorious invasive species (i.e., Centaurea maculosa). We found that, on a per-gram-of-biomass basis, each resident plant group similarly suppressed invader growth. Hence, with respect to preventing C. maculosa invasions, maintaining overall productivity is probably more important than maintaining the productivity of particular plant groups or species. But at the sites we studied, all plant groups may be needed to maintain overall productivity because removing forbs decreased overall productivity in two of three years. Alternatively, removing forbs increased productivity in another year, and this led us to posit that removing forbs may inflate the temporal productivity variance as opposed to greatly affecting time-averaged productivity. In either case, overall productivity responses to single plant group removals were inconsistent and fairly modest, and only when all plant groups were removed did C. maculosa growth increase substantially over a no-removal treatment. As such, it seems that intense disturbances (e.g., prolonged drought, overgrazing) that deplete multiple plant groups may often be a prerequisite for C. maculosa invasion.

  2. Prescribed burning supports grassland biodiversity - A multi-species study

    Science.gov (United States)

    Valkó, Orsolya; Deák, Balázs; Magura, Tibor; Török, Péter; Kelemen, András; Tóth, Katalin; Horváth, Roland; Nagy, Dávid; Debnár, Zsuzsanna; Zsigrai, György; Kapocsi, István; Tóthmérész, Béla

    2017-04-01

    During ancient times, fire was an important factor shaping European landscapes. Nowadays, prescribed burning can be one of the most effective conservation tools for the management of open landscapes, controlling dominant species, reducing accumulated litter or decreasing wildfire risk. In a prescribed burning experiment, we studied the effects of fire on dry alkaline grasslands. We tested whether autumn prescribed burning can be an alternative conservation measure in these grasslands. We selected six sites in Hungary: in three sites, prescribed burning was applied in November 2011, while three sites remained unburnt. We studied the effects of fire on soil characteristics, plant biomass and on the vegetation and arthropod assemblages (isopods, spiders, ground beetles and rove beetles). Soluble salt content increased significantly in the burnt sites, but soil pH, organic matter, potassium and phosphorous did not change. We found that prescribed fire had several positive effects from the nature conservation viewpoint. Diversity and the number of flowering shoots were higher, and the cover of the dominant grass was lower in the burnt sites. Graminoid biomass was lower, while total, green and forb biomass were higher in the burnt plots compared to the control ones. Our findings suggest that prescribed burning fire did not harm arthropods; species-level analyses showed that out of the most abundant invertebrate species, the abundance of ten was not affected, one decreased and one increased after burning. Our findings highlight that mosaic prescribed fire is a viable management tool in open landscapes, because it supports plant diversity and does not threaten arthropods.

  3. A treasure of endemic fauna of Mauritius and Rodrigues

    NARCIS (Netherlands)

    Winters, Ria

    2011-01-01

    This publication deals with the endemic species of the Indian ocean islands of Mauritius and Rodrigues. The author describes the extinct and extant birds and animals in word and art. The book is illustrated with the authors drawings and paintings. Full colour.

  4. Trichomonad infection in endemic and introduced columbids in the Seychelles.

    Science.gov (United States)

    Bunbury, N

    2011-07-01

    Island endemic avifaunas face many threats, including the now well-documented impacts of pathogens. The impacts of pathogens on the endemic Seychelles avifauna, however, have been little studied. The protozoan parasite Trichomonas gallinae has been shown to reduce survival and reproductive success of the endemic Pink Pigeon Columba mayeri on the nearby island of Mauritius. I investigated trichomonad infection prevalence and pathogenicity in endemic Seychelles Blue Pigeons, Alectroenas pulcherrima, and two introduced species of columbid, the Madagascar Turtle-dove, Streptopelia picturata, and the Barred Ground Dove, Geopelia striata, on the Seychelles island of Mahé during September-October 2007. I asked whether: 1) trichomonad infections occur in these species; 2) prevalence varies among species; and 3) birds show any signs of pathogenicity consistent with tricho-monosis. I use the results to assess the potential threat of this pathogen to A. pulcherrima. All three species were infected with trichomonads, and the overall prevalence was 27.5%. Alectroenas pulcherrima had higher prevalence (47.1%) than the two introduced species combined (24.3%). No infected individuals showed any signs of disease. These findings suggest that trichomonad parasites should be considered as a potential disease threat to the A. pulcherrima population.

  5. Distribution and protection of endemic or threatened rodents ...

    African Journals Online (AJOL)

    highest in the south-western parts of the country, and hotspots of endemism cOincide with those of species rich- ness. However, Red ... species richness hotspot in the Succulent Karoo contains no existing reserves, whereas all Red Data Book spe- ... conserve all aspects of biodiversity, but of historical ad hoc decisions ...

  6. Small mammals distribution and diversity in a plague endemic area ...

    African Journals Online (AJOL)

    Small mammals play a role in plague transmission as hosts in all plague endemic areas. Information on distribution and diversity of small mammals is therefore important for plague surveillance and control in such areas. The objective of this study was to investigate small mammals' diversity and their distribution in plague ...

  7. Patterns of distribution and protection status of the endemic ...

    African Journals Online (AJOL)

    The majority of these endemics are small mammals and many are listed in the Red Data Book, especially those restricted to the Nama-and Succulent Karoo. This is of concern, as both areas are inadequately protected by the existing protected areas. The coastal forests also contain many Red Data Book species, particularly ...

  8. Biological Invasion and Loss of Endemic Biodiversity in the Thar ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 3. Nature Watch - Biological Invasion and Loss of Endemic Biodiversity in the Thar Desert. Ishwar Prakash. Feature Article Volume 6 Issue 3 March 2001 pp 76-85. Fulltext. Click here to view fulltext PDF. Permanent link:

  9. Allozyme diversity in Macbridea alba (Lamiaceae), an endemic Florida mint

    Science.gov (United States)

    M.J.W. Godt; Joan L. Walker; J.L. Hamrick

    2004-01-01

    Macbridea alba is a herbaceous perennial mint endemic to the panhandle region of Florida. We used starch gel electrophoresis to describe allozyme diversity and genetic structure in this federally threatened plant. Ten populations were analyzed, with an average sample size of 47 plants (range 41-48 plants) per population. Of the 22 loci analyzed, 11 (...

  10. Patterns of endemicity and range restriction among southern African ...

    African Journals Online (AJOL)

    Patterns of endemicity and range restriction among southern African coastal marine invertebrates. RJ Scott, CL Griffiths, TB Robinson. Abstract. Southern Africa supports a rich marine biota of 12 734 currently described marine species. Although the distribution and overall species-richness patterns of several component ...

  11. Evolution of endemism on a young tropical mountain

    NARCIS (Netherlands)

    Merckx, V.; Hendriks, K.; Beentjes, K.; Mennes, C.B.; Becking, L.E.; Geurts, R.

    2015-01-01

    Tropical mountains are hot spots of biodiversity and endemism1–3, but the evolutionary origins of their unique biotas are poorly understood4. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these

  12. The endemicity of dracunculiasis, transmission pattern and ecology ...

    African Journals Online (AJOL)

    Studies on the endemicity of dracunculiasis, it's transmission pattern and ecology of cyclopoid copepods in Ezza North Local Government Area of Ebonyi State Nigeria were carried out between January and December 2001. Of the 2226 persons examined in eight communities, 426 (19.1%) were infected. This included 24 ...

  13. Evolution of endemism on a young tropical mountain

    NARCIS (Netherlands)

    Merckx, Vincent S F T; Hendriks, Kasper P; Beentjes, Kevin K; Mennes, Constantijn B; Becking, Leontine E; Peijnenburg, Katja T C A; Afendy, Aqilah; Arumugam, Nivaarani; de Boer, Hugo; Biun, Alim; Buang, Matsain M; Chen, Ping-Ping; Chung, Arthur Y C; Dow, Rory; Feijen, Frida A A; Feijen, Hans; Feijen-van Soest, Cobi; Geml, József; Geurts, René; Gravendeel, Barbara; Hovenkamp, Peter; Imbun, Paul; Ipor, Isa; Janssens, Steven B; Jocqué, Merlijn; Kappes, Heike; Khoo, Eyen; Koomen, Peter; Lens, Frederic; Majapun, Richard J; Morgado, Luis N; Neupane, Suman; Nieser, Nico; Pereira, Joan T; Rahman, Homathevi; Sabran, Suzana; Sawang, Anati; Schwallier, Rachel M; Shim, Phyau-Soon; Smit, Harry; Sol, Nicolien; Spait, Maipul; Stech, Michael; Stokvis, Frank; Sugau, John B; Suleiman, Monica; Sumail, Sukaibin; Thomas, Daniel C; van Tol, Jan; Tuh, Fred Y Y; Yahya, Bakhtiar E; Nais, Jamili; Repin, Rimi; Lakim, Maklarin; Schilthuizen, Menno

    2015-01-01

    Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these

  14. Evolution of endemism on a young tropical mountain

    NARCIS (Netherlands)

    Merckx, V.S.F.T.; Hendriks, K.P.; Beentjes, K.K.; Mennes, C.B.; Becking, L.E.; Peijnenburg, K.T.C.A.; Afendy, A.; Arumugam, N.; de Boer, H.; Biun, A.; Buang, M.M.; Chen, P.P.; Chung, A.Y.C.; Dow, R..; Feijen, F.A.A.; Feijen, H.; Feijen-van Soest, C.; Geml, J.; Geurts, R.; Gravendeel, B.; Hovenkamp, P.; Imbun, P.; Ipor, I.; Janssens, S.B.; Jocqué, M.; Kappes, H.; Khoo, E.; Koomen, P.; Lens, F.; Majapun, R.J.; Morgado, L.N.; Neupane, S.; Nieser, N.; Pereira, J.T.; Rahman, H.; Sabran, S.; Sawang, A.; Schwallier, R.M.; Shim, P.S.; Smit, H.; Sol, N.; Spait, M.; Stech, M.; Stokvis, F.; Sugau, J.B.; Suleiman, M.; Sumail, S.; Thomas, D.C.; van Tol, J.; Tuh, F.Y.Y.; Yahya, B.E.; Nais, J.; Repin, R.; Lakim, M.; Schilthuizen, M.

    2015-01-01

    Tropical mountains are hot spots of biodiversity and endemism1, 2, 3, but the evolutionary origins of their unique biotas are poorly understood4. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of

  15. Genetic variability in the population of the endemic bee Anthophora ...

    African Journals Online (AJOL)

    The genetic diversity and spatial genetic population structure of the solitary bee Anthophora pauperata Walker 1871, a species endemic to St Katherine Protectorate, were studied by RAPD markers in seven wadis in the St Katherine Protectorate, South Sinai, Egypt. High levels of genetic diversity were found, mostly within ...

  16. Factors Affecting Agroforestry Sustainability in Bee Endemic Parts of ...

    African Journals Online (AJOL)

    This paper attempts, in an exploratory manner, to identify the various ways in which bad beekeeping and honey hunting practices result in the loss of important multi-purpose agro-forestry tree species in bee endemic parts of South Eastern Nigeria. Both qualitative and quantitative approaches (Participatory Rural Appraisal ...

  17. Distribution and protection of endemic or threatened rodents ...

    African Journals Online (AJOL)

    Species richness of the target species is highest in the south-western parts of the country, and hotspots of endemism coincide with those of species richness. However, Red Data Book species hotspots are confined to the north-eastern parts of the country. One species richness hotspol in the Succulent Karoo contains no ...

  18. Evaluation of hospital disinfection as a means of controlling endemic ...

    African Journals Online (AJOL)

    Evaluation of hospital environment disinfection as a means of controlling endemic nosocomial pathogens in a University Teaching Hospital in Nigeria was evaluated. Disinfectant used in the Hospital was collected from the Infection Control unit and prepared in different concentrations. The isolated bacterial species from the ...

  19. Historic forests and endemic mountain pine beetle and dwarf mistletoe

    Science.gov (United States)

    Jose Negron

    2012-01-01

    Mountain pine beetle has always been a significant disturbance agent in ponderosa and lodgepole pine forests in Colorado. Most studies have examined the impacts to forest structure associated with epidemic populations of a single disturbance agent. In this paper we address the role of endemic populations of mountain pine and their interactions with dwarf mistletoe...

  20. Cotrimoxazole for childhood febrile illness in Malaria-endemic regions

    African Journals Online (AJOL)

    ren younger than 5 years of age was evaluated in. Malawi. ... limitations in diagnostic technology and personnel, disease-specific clinical ... In practice, the World. Health Organisation (WHO) recommends that in highly endemic areas all young children with fever should be treated for malaria, because of the likeli- hood of ...

  1. Investigating The Travelling Wave Solution For an SIR Endemic ...

    African Journals Online (AJOL)

    This paper presents the travelling wave solution for an SIR endemic disease model with no disease related death when the spatial spread of the susceptible is not negligible. In this case the disease is driven by both the susceptible and the infective classes. The population is open since the disease is habitually prevalent in ...

  2. An Investigation on the antimicrobial activity of some endemic plant ...

    African Journals Online (AJOL)

    In this study performed on six endemic plant species, antimicrobial activity was observed in Campanula lyrata subsp.lyrata and Abies nordmanniana subsp. bornmuelleriana plants. The minimum inhibitory concentration of C. lyrata subsp. lyrata (leaf and flower) extract was found to be 29 mg/ml for Baccillus subtilis and 14.5 ...

  3. Rediscovery of Curcuma sumatrana (Zingiberaceae) endemic to West Sumatra

    NARCIS (Netherlands)

    Ardiyani, M.; Anggara, A.; Leong-Škorničková, J.

    2011-01-01

    A recent exploration of Sumatra resulted in the re-collection of Curcuma sumatrana, an endemic Zingiberaceae species of unclear identity that was first described by Miquel nearly 150 years ago. The history of this species is discussed, a detailed description with a colour plate is provided and a

  4. Clostridium difficile infection in an endemic setting in the Netherlands

    NARCIS (Netherlands)

    Hensgens, M. P. M.; Goorhuis, A.; van Kinschot, C. M. J.; Crobach, M. J. T.; Harmanus, C.; Kuijper, E. J.

    2011-01-01

    The purpose of this investigation was to study risk factors for Clostridium difficile infection (CDI) in an endemic setting. In a 34-month prospective case-control study, we compared the risk factors and clinical characteristics of all consecutively diagnosed hospitalised CDI patients (n = 93) with

  5. Conservation assessment of the endemic plants from Kosovo

    Directory of Open Access Journals (Sweden)

    Millaku Fadil

    2017-06-01

    Full Text Available Sixteen endemic plant taxa were selected from Kosovo, according to the IUCN standards and for each taxon the risk assessment and threat category has been assigned. The taxa were compared with their previous status from fifteen years ago. From sixteen plant taxa, which were included in this work, four are Balkan endemics, whereas, eight of them are local endemics and four of the taxa are stenoendemics. Six of the taxa are grown exclusively on serpentine soils, five of them on limestone substrate, four of them in carbonate substrate, yet only one in silicate substrate. The work has been done based on the standard working methodologies of the IUCN (Guidelines for Using the IUCN Red List Categories and Criteria – Version 8.1. The most threatened plant taxa is Solenanthus krasniqii – which after its observance has only 20 mature individuals. As a result of the wild collection of the medicinal and aromatic plants, from the local population, Sideritis scardica is about to be completely go extinct. The aim of this study was to assess the state of endemics in the threats possessed to them during the previous times, present and predicting the trends for the upcoming years.

  6. 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.

  7. Faeco-histological Method of Studying Worm Endemicity with the ...

    African Journals Online (AJOL)

    Worms are endemic in various parts of the world, the patterns varying from community to community, even in the same country. A rough index of those common among Nigerians of the Igbo ethnic group has been obtained using a histological study of the ova present in the luminal faeces of the vermiform appendix in 559 ...

  8. Evaporation from Pinus caribaea plantations on former grassland soils under maritime tropical conditions.

    NARCIS (Netherlands)

    Waterloo, M.J.; Bruijnzeel, L.A.; Vugts, H.F.; Rawaqa, T.T.

    1999-01-01

    Wet canopy and dry canopy evaporation from young and mature plantations of Pinus caribaea on former grassland soils under maritime tropical conditions in southwestern Viti Levu, Fiji, were determined using micrometeorological and hydrological techniques. Modeled annual evaporation totals (ET) of

  9. Evaporation from Pinus caribaea plantations on former grassland soils under maritime tropical conditions

    NARCIS (Netherlands)

    Waterloo, M.J.; Bruijnzeel, L.A.; Vugts, H.F.; Rawaqa, T.T.

    1999-01-01

    Wet canopy and dry canopy evaporation from young and mature plantations of Pinus caribaea on former grassland soils under maritime tropical conditions in southwestern Viti Levu, Fiji, were determined using micrometeorological and hydrological techniques. Modeled annual evaporation totals (ET) of

  10. NPP Grassland: Beacon Hill, U.K., 1972-1993, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains two ASCII text files, one providing productivity measurements for a chalk grassland on Beacon Hill, West Sussex, U.K. (50.92 N, -0.85 W) and...

  11. Soil communities promote temporal stability and species asynchrony in experimental grassland communities

    NARCIS (Netherlands)

    Pellkofer, Sarah; Van Der Heijden, Marcel G A; Schmid, Bernhard; Wagg, Cameron

    2016-01-01

    Background Over the past two decades many studies have demonstrated that plant species diversity promotes primary productivity and stability in grassland ecosystems. Additionally, soil community characteristics have also been shown to influence the productivity and composition of plant communities,

  12. Seasonal dynamics and vertical distribution of plant-feeding nematode communities in grasslands

    NARCIS (Netherlands)

    Verschoor, B.C.; Goede, de R.G.M.; Hoop, de J.W.; Vries, de F.W.

    2001-01-01

    The vertical distribution and seasonal dynamics of plant- and fungal-feeding nematode taxa in permanent grasslands were investigated. Dolichodoridae, Paratylenchus, Pratylenchus, Tylenchidae and Aphelenchoides dominated the upper 10 cm soil and their numbers strongly decreased with depth. The

  13. Threshold responses to interacting global changes in a California grassland ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Field, Christopher [Carnegie Inst. of Science, Stanford, CA (United States); Mooney, Harold [Stanford Univ., CA (United States); Vitousek, Peter [Stanford Univ., CA (United States)

    2015-02-02

    Building on the history and infrastructure of the Jasper Ridge Global Change Experiment, we conducted experiments to explore the potential for single and combined global changes to stimulate fundamental type changes in ecosystems that start the experiment as California annual grassland. Using a carefully orchestrated set of seedling introductions, followed by careful study and later removal, the grassland was poised to enable two major kinds of transitions that occur in real life and that have major implications for ecosystem structure, function, and services. These are transitions from grassland to shrubland/forest and grassland to thistle patch. The experiment took place in the context of 4 global change factors – warming, elevated CO2, N deposition, and increased precipitation – in a full-factorial array, present as all possible 1, 2, 3, and 4-factor combinations, with each combination replicated 8 times.

  14. Monitoring Grassland Tourist Season of Inner Mongolia, China Using Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Quansheng Ge

    2014-01-01

    Full Text Available Phenology-driven events, such as spring wildflower displays or fall tree colour, are generally appreciated by tourists for centuries around the world. Monitoring when tourist seasons occur using satellite data has been an area of growing research interest in recent decades. In this paper, a valid methodology for detecting the grassland tourist season using remote sensing data was presented. On average, the beginning, the best, and the end of grassland tourist season of Inner Mongolia, China, occur in late June (±30 days, early July (±30 days, and late July (±50 days, respectively. In south region, the grassland tourist season appeared relatively late. The length of the grassland tourist season is about 90 days with strong spatial trend. South areas exhibit longer tourist season.

  15. Plant species occurrence patterns in Eurasian grasslands reflect adaptation to nutrient ratios

    NARCIS (Netherlands)

    Roeling, Ineke S.; Ozinga, Wim A.; van Dijk, Jerry; Eppinga, Maarten B.; Wassen, Martin J.

    2018-01-01

    Previous studies of Eurasian grasslands have suggested that nutrient ratios, rather than absolute nutrient availabilities and associated productivity, may be driving plant species richness patterns. However, the underlying assumption that species occupy distinct niches along nutrient ratio gradients

  16. Spontaneous colonization of restored dry grasslands by target species: restoration proceeds beyond sowing regional seed mixtures

    Czech Academy of Sciences Publication Activity Database

    Johanidesová, E.; Fajmon, K.; Jongepierová, I.; Prach, Karel

    2015-01-01

    Roč. 70, č. 4 (2015), s. 631-638 ISSN 0142-5242 Institutional support: RVO:67985939 Keywords : restoration * grasslands * spontaneous colonization Subject RIV: EH - Ecology, Behaviour Impact factor: 1.617, year: 2015

  17. PCDD/F and Aromatic Emissions from Simulated Forest and Grassland Fires

    Science.gov (United States)

    Emissions of polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/F) from simulated grassland and forest fires were quantitatively sampled to derive emission factors in support of PCDD/F inventory development. Grasses from Kentucky and Minnesota; forest shrubs fro...

  18. Strategic Grassland Bird Conservation throughout the annual cycle: Linking policy alternatives, landowner decisions, and biological population outcomes

    Science.gov (United States)

    Drum, Ryan G.; Ribic, Christine; Koch, Katie; Lonsdorf, Eric V.; Grant, Edward C.; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, D.C.; Rideout, Catherine; Sample, David W.

    2015-01-01

    Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds.

  19. Strategic Grassland Bird Conservation throughout the Annual Cycle: Linking Policy Alternatives, Landowner Decisions, and Biological Population Outcomes.

    Directory of Open Access Journals (Sweden)

    Ryan G Drum

    Full Text Available Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds.

  20. Future of endemic flora of biodiversity hotspots in India.

    Directory of Open Access Journals (Sweden)

    Vishwas Sudhir Chitale

    Full Text Available India is one of the 12 mega biodiversity countries of the world, which represents 11% of world's flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Western Ghats, Indo-Burma, based on A1B scenario for year 2050 and 2080. We develop individual variable based models as well as mixed models in MaxEnt by combining ten least co-related bioclimatic variables, two disturbance variables and one physiography variable as predictor variables. The projected changes suggest that the endemic flora will be adversely impacted, even under such a moderate climate scenario. The future distribution is predicted to shift in northern and north-eastern direction in Himalaya and Indo-Burma, while in southern and south-western direction in Western Ghats, due to cooler climatic conditions in these regions. In the future distribution of endemic plants, we observe a significant shift and reduction in the distribution range compared to the present distribution. The model predicts a 23.99% range reduction and a 7.70% range expansion in future distribution by 2050, while a 41.34% range reduction and a 24.10% range expansion by 2080. Integration of disturbance and physiography variables along with bioclimatic variables in the models improved the prediction accuracy. Mixed models provide most accurate results for most of the combinations of climatic and non-climatic variables as compared to individual variable based models. We conclude that a regions with cooler climates and higher moisture availability could serve as refugia for endemic plants in future climatic conditions; b mixed models provide more accurate results, compared to single

  1. Future of endemic flora of biodiversity hotspots in India.

    Science.gov (United States)

    Chitale, Vishwas Sudhir; Behera, Mukund Dev; Roy, Partha Sarthi

    2014-01-01

    India is one of the 12 mega biodiversity countries of the world, which represents 11% of world's flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Western Ghats, Indo-Burma, based on A1B scenario for year 2050 and 2080. We develop individual variable based models as well as mixed models in MaxEnt by combining ten least co-related bioclimatic variables, two disturbance variables and one physiography variable as predictor variables. The projected changes suggest that the endemic flora will be adversely impacted, even under such a moderate climate scenario. The future distribution is predicted to shift in northern and north-eastern direction in Himalaya and Indo-Burma, while in southern and south-western direction in Western Ghats, due to cooler climatic conditions in these regions. In the future distribution of endemic plants, we observe a significant shift and reduction in the distribution range compared to the present distribution. The model predicts a 23.99% range reduction and a 7.70% range expansion in future distribution by 2050, while a 41.34% range reduction and a 24.10% range expansion by 2080. Integration of disturbance and physiography variables along with bioclimatic variables in the models improved the prediction accuracy. Mixed models provide most accurate results for most of the combinations of climatic and non-climatic variables as compared to individual variable based models. We conclude that a) regions with cooler climates and higher moisture availability could serve as refugia for endemic plants in future climatic conditions; b) mixed models provide more accurate results, compared to single variable based

  2. Specialist plant species harbour higher reproductive performances in recently restored calcareous grasslands than in reference habitats

    OpenAIRE

    Harzé, Mélanie; Mahy, Grégory; Bizoux, Jean-Philippe; Piqueray, Julien; Monty, Arnaud

    2015-01-01

    Background and aims_Calcareous grasslands are local biodiversity hotspots in temperate regions that suffered intensive fragmentation. Ecological restoration projects took place all over Europe. Their success has traditionally been assessed using a plant community approach. However, population ecology can also be useful to assess restoration success and to understand underlying mechanisms. Methods_We took advantage of three calcareous grassland sites in Southern Belgium, where reference p...

  3. Extensive Management Promotes Plant and Microbial Nitrogen Retention in Temperate Grassland

    Science.gov (United States)

    de Vries, Franciska T.; Bloem, Jaap; Quirk, Helen; Stevens, Carly J.; Bol, Roland; Bardgett, Richard D.

    2012-01-01

    Leaching losses of nitrogen (N) from soil and atmospheric N deposition have led to widespread changes in plant community and microbial community composition, but our knowledge of the factors that determine ecosystem N retention is limited. A common feature of extensively managed, species-rich grasslands is that they have fungal-dominated microbial communities, which might reduce soil N losses and increase ecosystem N retention, which is pivotal for pollution mitigation and sustainable food production. However, the mechanisms that underpin improved N retention in extensively managed, species-rich grasslands are unclear. We combined a landscape-scale field study and glasshouse experiment to test how grassland management affects plant and soil N retention. Specifically, we hypothesised that extensively managed, species-rich grasslands of high conservation value would have lower N loss and greater N retention than intensively managed, species-poor grasslands, and that this would be due to a greater immobilisation of N by a more fungal-dominated microbial community. In the field study, we found that extensively managed, species-rich grasslands had lower N leaching losses. Soil inorganic N availability decreased with increasing abundance of fungi relative to bacteria, although the best predictor of soil N leaching was the C/N ratio of aboveground plant biomass. In the associated glasshouse experiment we found that retention of added 15N was greater in extensively than in intensively managed grasslands, which was attributed to a combination of greater root uptake and microbial immobilisation of 15N in the former, and that microbial immobilisation increased with increasing biomass and abundance of fungi. These findings show that grassland management affects mechanisms of N retention in soil through changes in root and microbial uptake of N. Moreover, they support the notion that microbial communities might be the key to improved N retention through tightening linkages

  4. Energy production from grassland - Assessing the sustainability of different process chains under German conditions

    International Nuclear Information System (INIS)

    Roesch, Christine; Skarka, J.; Raab, K.; Stelzer, V.

    2009-01-01

    In many regions of Europe, grassland shapes the landscape and fulfils important functions in protecting nature, soil, and water. However, the traditional uses of grassland for forage production are vanishing with progress in breeding and structural adaptations in agriculture. On the other hand, the demand for biomass energy is rising due to political sustainability goals and financial measures to support renewable energy. Against this background, the Institute for Technology Assessment and Systems Analysis investigated the applicability, economic efficiency, and sustainability of different techniques for energy production from grassland as well as from grassland converted into maize fields or short-rotation poplars under German conditions. The results show that despite relatively high energy prices and the financial support for bioenergy, the effects of energy production from grassland on employment in agriculture and farmers' income are modest. What is beneficial are savings in non-renewable energy, reductions in greenhouse gas emissions, and local provision of energy carriers. If grassland biomass (grass silage or hay) is used for energy purposes, this brings the further advantages of preserving biodiversity and the cultural landscape and protecting of soil and groundwater. Negative impacts on sustainable development result from an increase in emissions, which leads to acidification, eutrophication, and risks to human health. The overall evaluation indicates that short-rotation poplars are comparatively advantageous from the economic and ecological point of view. Therefore, a development plan for grassland is required to identify areas where grassland could be used as an energy resource or where it would be favourable to install energy plantations with fast-growing perennial plants

  5. Pollination biology in a tropical high-altitude grassland in Brazil: Interactions at the community level

    OpenAIRE

    Freitas, L; Sazima, M

    2006-01-01

    Surveys of local assemblages of plants and their pollinators are among the most useful ways to evaluate specialization in pollination and to discuss the patterns of plant-pollinator interactions among ecosystems. The high-altitude grasslands from southeastern Brazil constitute diminutive island-like formations surrounded by montane rainforests. We registered the floral traits of 124 species from the Serra da Bricaina grasslands (about 60% of the animal-pollinated species of this flora), and d...

  6. Farming for pests? Local and landscape-scale effects of grassland management on rabbit densities

    OpenAIRE

    Petrovan , Silviu O.; Barrio , Isabel C.; Ward , Alastair I.; Wheeler , Philip M.

    2010-01-01

    Abstract In recent decades in the UK, there has been an increasing trend in numbers of the European wild rabbit, a significant agricultural pest typically associated with grassland habitats. However, the relationship between rabbit abundance and grassland management, in particular grazing, has not been sufficiently explained. We studied rabbit densities in seven pasture-dominated sites in north-east England between autumn and spring in two consecutive years, and used generalised li...

  7. Responses of soil fungal community to the sandy grassland restoration in Horqin Sandy Land, northern China.

    Science.gov (United States)

    Wang, Shao-Kun; Zuo, Xiao-An; Zhao, Xue-Yong; Li, Yu-Qiang; Zhou, Xin; Lv, Peng; Luo, Yong-Qing; Yun, Jian-Ying

    2016-01-01

    Sandy grassland restoration is a vital process including re-structure of soils, restoration of vegetation, and soil functioning in arid and semi-arid regions. Soil fungal community is a complex and critical component of soil functioning and ecological balance due to its roles in organic matter decomposition and nutrient cycling following sandy grassland restoration. In this study, soil fungal community and its relationship with environmental factors were examined along a habitat gradient of sandy grassland restoration: mobile dunes (MD), semi-fixed dunes (SFD), fixed dunes (FD), and grassland (G). It was found that species abundance, richness, and diversity of fungal community increased along with the sandy grassland restoration. The sequences analysis suggested that most of the fungal species (68.4 %) belonged to the phylum of Ascomycota. The three predominant fungal species were Pleospora herbarum, Wickerhamomyces anomalus, and Deconica Montana, accounting for more than one fourth of all the 38 species. Geranomyces variabilis was the subdominant species in MD, Pseudogymnoascus destructans and Mortierella alpine were the subdominant species in SFD, and P. destructans and Fungi incertae sedis were the dominant species in FD and G. The result from redundancy analysis (RDA) and stepwise regression analysis indicated that the vegetation characteristics and soil properties explain a significant proportion of the variation in the fungal community, and aboveground biomass and C:N ratio are the key factors to determine soil fungal community composition during sandy grassland restoration. It was suggested that the restoration of sandy grassland combined with vegetation and soil properties improved the soil fungal diversity. Also, the dominant species was found to be alternative following the restoration of sandy grassland ecosystems.

  8. Effect of soil properties and hydrology on Archaeal community composition in three temperate grasslands on peat

    DEFF Research Database (Denmark)

    Görres, Carolyn-Monika; Conrad, Ralf; Petersen, Søren O

    2013-01-01

    Grasslands established on drained peat soils are regarded as negligible methane (CH4) sources; however, they can still exhibit considerable soil CH4 dynamics. We investigated archaeal community composition in two different fen peat soils and one bog peat soil under permanent grassland in Denmark........ Overall, there seemed to be a significant coupling between peat type and archaeal community composition, with local hydrology modifying the strength of this coupling....

  9. Moderate and high endemicity of schistosomiasis is a predictor of the endemicity of soil-transmitted helminthiasis - Systematic review

    Science.gov (United States)

    Yajima, A.; Gabrielli, A. F.; Montresor, A.; Engels, D.

    2017-01-01

    The authors conducted a systematic literature review with the following aims: (i) to investigate how frequently soil-transmitted helminthiasis (STH) infections are endemic where schistosomiasis is present; and (ii) to assess the correlation between the risk level of schistosomiasis and that of STH. Among 155 sites on which data were collected and analyzed, schistosomiasis was present in 130 sites, all of which were also co-endemic for STH, whereas 25 sites were endemic only for STH. Out of 83 sites where at least one biannual round of preventive chemotherapy (PC) for schistosomiasis is recommended, 94% were also eligible for at least a yearly round of PC against STH. And among 21 sites where PC for schistosomiasis is recommended once a year, 81% were also eligible for at least a yearly round of PC for STH. This fact provides managers of control programmes with the operationally important indication that use of available information on endemicity of schistosomiasis is a valid tool to predict the presence of STH in the same geographical area as well as to estimate the need of PC for STH. The implementation of this tool is expected to save financial and human resources and help accelerate the scale-up of PC throughout the world. PMID:21215979

  10. Moderate and high endemicity of schistosomiasis is a predictor of the endemicity of soil-transmitted helminthiasis: a systematic review.

    Science.gov (United States)

    Yajima, A; Gabrielli, A F; Montresor, A; Engels, D

    2011-02-01

    The authors conducted a systematic literature review with the following aims: to investigate how frequently soil-transmitted helminthiasis (STH) infections are endemic where schistosomiasis is present; and to assess the correlation between the risk level of schistosomiasis and that of STH. Among 155 sites on which data were collected and analyzed, schistosomiasis was present in 130, all of which were also co-endemic for STH, whereas 25 sites were endemic only for STH. Ninety percent (117 out of 130) of the areas eligible for preventive chemotherapy (PC) against schistosomiasis are also eligible for PC against STH. This fact provides managers of control programmes with the operationally important indication that use of available information on endemicity of schistosomiasis is a valid tool to predict the presence of STH in the same geographical area and to estimate the need of PC for STH. The implementation of this tool is expected to save financial and human resources and help accelerate the scale-up of PC throughout the world. Copyright © 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  11. Grassland habitat restoration: lessons learnt from long term monitoring of Swanworth Quarry, UK, 1997–2014

    Directory of Open Access Journals (Sweden)

    Barbara Maria Smith

    2017-11-01

    Full Text Available Habitat restoration projects are often conducted when prior use or extraction of natural resources results in land degradation. The success of restoration programmes, however, is variable, and studies that provide evidence of long term outcomes are valuable for evaluation purposes. This study focused on the restoration of vegetation within a limestone quarry in Dorset, UK between 1997 and 2014. Using a randomised block design, the effect of seed mix and seed rate on the development of community assemblage was investigated in comparison to a nearby target calcareous grassland site. We hypothesised that seed mix composition and sowing rate would influence both the trajectory of the grassland assemblage and final community composition. We found that species composition (in relation to both richness and community assemblage was strongly influenced by time and to some extent by seed rate and seed mix. However, no treatments achieved strong resemblance to the calcareous grassland target vegetation; rather they resembled mesotrophic communities. We conclude that (as with previous studies there is no “quick fix” for the establishment of a grassland community; long-term monitoring provides useful information on the trajectory of community development; sowing gets you something (in our case mesotrophic grassland, but, it may not be the target vegetation (e.g., calcicolous grassland you want that is difficult to establish and regenerate; it is important to sow a diverse mix as subsequent recruitment opportunities are probably limited; post-establishment management should be explored further and carefully considered as part of a restoration project.

  12. Striking a balance: socioeconomic development and conservation in grassland through community-based zoning.

    Directory of Open Access Journals (Sweden)

    Craig Leisher

    Full Text Available The goal of preserving nature is often in conflict with economic development and the aspirations of the rural poor. Nowhere is this more striking than in native grasslands, which have been extensively converted until a mere fraction of their original extent remains. This is not surprising; grasslands flourish in places coveted by humans, primed for agriculture, plantations, and settlements that nearly always trump conservation efforts. The Umgano grassland conservation and poverty reduction project in KwaZulu-Natal Province, South Africa uses community-based spatial planning to balance the conversion of its lower-conservation value grasslands to a timber plantation, while conserving higher-value grasslands for heritage purposes and managed livestock grazing. Ten years after project launch, we measured the ecological and socioeconomic impacts of the project using Normalized Differential Vegetation Index remote sensing data and over 500 household interviews, as compared with similar non-conserved areas. Zoned management of the Umgano area had resulted in between 9% and 17% greater average peak production in the grassland areas compared to control sites. There was also a 21% gain in incomes for the roughly one hundred people employed by the forestry efforts, when compared to others in their village. Community-based spatial zoning is an overlooked tool for balancing conservation and development but may require, as we found in Umgano, certain critical factors including strong local leadership, an accountable financial management mechanism to distribute income, outside technical expertise for the zoning design, and community support.

  13. Research priorities for grassland science: the need of long term integrated experiments networks

    Directory of Open Access Journals (Sweden)

    G. Lemaire

    2007-07-01

    Full Text Available Grasslands have to be considered not only as a mean for providing foods for domestic herbivore but also as an important biome of terrestrial biosphere. This function of grasslands as an active component of our environment requires specific studies on the role and impact of this ecosystem on soil erosion and soil quality, quality and quantity of water resources, atmosphere composition and greenhouse gas emission or sequestration, biodiversity dynamics at different scales from field plot to landscape. All these functions have to be evaluated in conjunction with the function of providing animal products for increasing human population. So multifunctionality of grasslands become a new paradigm for grassland science. Environmental and biodiversity outputs require long term studies, being the long term retro-active processes within soil, vegetation and micro-organism communities in relation to changes in management programme. So grassland science needs to carry on long term integrated experimentation for studying all the environmental outputs and ecological services associated to grassland management systems.

  14. Increasing temperature reduces the coupling between available nitrogen and phosphorus in soils of Chinese grasslands

    Science.gov (United States)

    Geng, Yan; Baumann, Frank; Song, Chao; Zhang, Mi; Shi, Yue; Kühn, Peter; Scholten, Thomas; He, Jin-Sheng

    2017-03-01

    Changes in climatic conditions along geographical gradients greatly affect soil nutrient cycling processes. Yet how climate regimes such as changes in temperature influence soil nitrogen (N) and phosphorus (P) concentrations and their stoichiometry is not well understood. This study investigated the spatial pattern and variability of soil N and P availability as well as their coupling relationships at two soil layers (0-10 and 10-20 cm) along a 4000-km climate transect in two grassland biomes of China, the Inner Mongolian temperate grasslands and the Tibetan alpine grasslands. Our results found that in both grasslands, from cold to warm sites the amounts of soil total N, total P and available P all decreased. By contrast, the amount of available N was positively related to mean annual temperature in the Tibetan grasslands. Meanwhile, with increasing temperature ratio of available N to P significantly increased but the linear relationship between them was considerably reduced. Thus, increasing temperature may not only induce a stoichiometric shift but also loose the coupling between available N and P. This N-P decoupling under warmer conditions was more evident in the Tibetan alpine grasslands where P limitation might become more widespread relative to N as temperatures continue to rise.

  15. Effects of the endemic earthworm .i.Allolobophora hrabei./i. (Černosvitov, 1935) on soil microbial communities of steppe grasslands

    Czech Academy of Sciences Publication Activity Database

    Jirout, Jiří; Pižl, Václav

    2014-01-01

    Roč. 76, September (2014), s. 249-256 ISSN 0038-0717 R&D Projects: GA ČR GAP504/12/0536 Institutional support: RVO:60077344 Keywords : bacteria * archaea * fungi * community composition * DGGE * earthworm Subject RIV: EH - Ecology, Behaviour Impact factor: 3.932, year: 2014

  16. Are there different requirements for trace elements in eumelanin- and pheomelanin-based color production? A case study of two passerine species.

    Science.gov (United States)

    Zduniak, Piotr; Surmacki, Adrian; Erciyas-Yavuz, Kiraz; Chudzińska, Maria; Barałkiewicz, Danuta

    2014-09-01

    Melanin is the most common pigment in animal integuments including bird plumage. It has been shown that several trace elements may play roles in the production and signaling function of melanin-colored plumage. We investigated coloration and content of various metal elements in the rectrices of two insectivorous passerines, Common Redstarts (Phoenicurus phoenicurus) and Blackcaps (Sylvia atricapilla), which have eumelanin- and pheomelanin-based coloration, respectively. We hypothesized that 1) the two species would differ in concentrations of metals important in melanin synthesis (Ca, Fe, Cu, Zn), 2) differences in metal concentration levels would be related to feather coloration. Our study confirmed the first prediction and provides the first evidence that selected elements may play a greater role in pheomelanin than in eumelanin synthesis. Concentrations of three elements considered as important in melanin synthesis (Ca, Fe, Zn) were 52% to 93% higher in rusty colored Common Redstart feathers compared to the dark gray Blackcap feathers. However, element concentrations were not correlated with feather coloration or sex in either species. Our study suggests that, of the two melanin forms, pheomelanin synthesis may bear higher costs associated with the acquisition of specific elements or limited elements may create trade-offs between ornamentation and other physiological functions. Our findings warrant further investigations designed to better understand the roles of macro- and microelements in the synthesis of both forms of melanin. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Genetic connectivity and self-replenishment of inshore and offshore populations of the endemic anemonefish, Amphiprion latezonatus

    KAUST Repository

    Steinberg, Rosemary; van der Meer, Martin; Walker, Emily; Berumen, Michael L.; Hobbs, Jean-Paul A.; van Herwerden, Lynne

    2016-01-01

    and small distribution ranges (endemics). Marine endemics often exist as meta-populations distributed among few isolated locations. Determining genetic connectivity among these locations is essential to understanding the recovery potential of endemics after

  18. Effects of natural phenomena and human activity on the species richness of endemic and non-endemic Heteroptera in the Canary Islands

    Directory of Open Access Journals (Sweden)

    Vargas, J. M.

    2004-12-01

    Full Text Available The geographical patterns of Heteroptera species diversity in the Canary Islands were analysed, and endemic and non–endemic species were studied both together and separately. Causal processes most likely controlling these patterns, as well as the theory of island biogeography, hypotheses about evolutionary time, habitat heterogeneity, climatic stability, intermediate disturbances, energy, environmental favourableness–severity, productivity and human influence were investigated. The combination of habitat heterogeneity and human influence accounted for the total number of species. However, when endemic and non–endemic species were analysed separately, habitat heterogeneity and favourableness–severity explained the richness of endemic species, whereas habitat heterogeneity and human influence explained that of non–endemic species.

  19. Using Remotely Sensed Fluorescence and Soil Moisture to Better Understand the Seasonal Cycle of Tropical Grasslands

    Science.gov (United States)

    Smith, Dakota Carlysle

    Seasonal grasslands account for a large area of Earth's land cover. Annual and seasonal changes in these grasslands have profound impacts on Earth's carbon, energy, and water cycles. In tropical grasslands, growth is commonly water-limited and the landscape oscillates between highly productive and unproductive. As the monsoon begins, soils moisten providing dry grasses the water necessary to photosynthesize. However, along with the rain come clouds that obscure satellite products that are commonly used to study productivity in these areas. To navigate this issue, we used solar induced fluorescence (SIF) products from OCO-2 along with soil moisture products from the Soil Moisture Active Passive satellite (SMAP) to "see through" the clouds to monitor grassland productivity. To get a broader understanding of the vegetation dynamics, we used the Simple Biosphere Model (SiB4) to simulate the seasonal cycles of vegetation. In conjunction with SiB4, the remotely sensed SIF and soil moisture observations were utilized to paint a clearer picture of seasonal productivity in tropical grasslands. The remotely sensed data is not available for every place at one time or at every time for one place. Thus, the study was focused on a large area from 15° E to 35° W and from 8°S to 20°N in the African Sahel. Instead of studying productivity relative to time, we studied it relative to soil moisture. Through this investigation we found soil moisture thresholds for the emergence of grassland growth, near linear grassland growth, and maturity of grassland growth. We also found that SiB4 overestimates SIF by about a factor of two for nearly every value of soil moisture. On the whole, SiB4 does a surprisingly good job of predicting the response of seasonal growth in tropical grasslands to soil moisture. Future work will continue to integrate remotely sensed SIF & soil moisture with SiB4 to add to our growing knowledge of carbon, water, and energy cycling in tropical grasslands.

  20. Seasonal/Interannual Variations of Carbon Sequestration and Carbon Emission in a Warm-Season Perennial Grassland

    OpenAIRE

    Deepa Dhital; Tomoharu Inoue; Hiroshi Koizumi

    2014-01-01

    Carbon sequestration and carbon emission are processes of ecosystem carbon cycling that can be affected while land area converted to grassland resulting in increased soil carbon storage and below-ground respiration. Discerning the importance of carbon cycle in grassland, we aimed to estimate carbon sequestration in photosynthesis and carbon emission in respiration from soil, root, and microbes, for four consecutive years (2007–2010) in a warm-season perennial grassland, Japan. Soil carbon emi...

  1. On the origin of endemic species in the Red Sea

    KAUST Repository

    DiBattista, Joseph; Howard Choat, J.; Gaither, Michelle R.; Hobbs, Jean-Paul A.; Lozano-Corté s, Diego; Myers, Robert F.; Paulay, Gustav; Rocha, Luiz A.; Toonen, Robert J.; Westneat, Mark W.; Berumen, Michael L.

    2015-01-01

    High endemism observed in the Red Sea and Gulf of Aden appears to have multiple origins. A cold, nutrient-rich water barrier separates the Gulf of Aden from the rest of the Arabian Sea, whereas a narrow strait separates the Red Sea from the Gulf of Aden, each providing potential isolating barriers. Additional barriers may arise from environmental gradients, circulation patterns and the constriction at the mouth of the Gulf of Aqaba. Endemics that evolved within the Red Sea basin had to survive glacial cycles in relatively low salinity refugia. It therefore appears that the unique conditions in the Red Sea, in addition to those characteristics of the Arabian Peninsula region as a whole, drive the divergence of populations via a combination of isolation and selection.

  2. Responses to TRH in patients with endemic goiter

    International Nuclear Information System (INIS)

    Carneiro, Laureano; Watanabe, Tomas; El Tamer, Elias; Varela, Amalia; Moran, Dardo; Rinaudo, Antonio; Staneloni, Luis; Degrossi, O.J.

    1978-12-01

    The response to TRH was studied in 32 patients from an endemic goiter area, 20 of them had been previously treated with iodized oil. Blood samples were taken at 0, 20, 40 and 120 minutes after de i.v. administration of 400μg of TRH, and serum levels of TSH, T3 and T4 were measured. The results obtained show that in endemic goiter area there is a modification in the hypothalamus-pituitary-thyroid feedback mechanism, with increased reserve of pituitary TSH and changes in T4 and T3 secretion. The injection of TRH gave exaggerated and delayed responses in the secretion of TSH and T3. Iodized oil used as a prophylatic method produced a disminution of pituitary TSH reserve, and of serum levels of TSH and T3, as a result of the return tonormality of the hypothalamus-pituitary-thyroid feedback mechanism. (author) [es

  3. Measuring denitrification after grassland renewal and grassland conversion to cropland by using the 15N gas-flux method

    Science.gov (United States)

    Buchen, Caroline; Eschenbach, Wolfram; Flessa, Heinz; Giesemann, Anette; Lewicka-Szczebak, Dominika; Well, Reinhard

    2015-04-01

    Denitrification, the reduction of oxidized forms of inorganic N to N2O and N2 is an important pathway of gaseous nitrogen losses. Measuring denitrification, especially the reduction of N2O to N2, expressed in the product ratio (N2O/(N2O + N2)), is rather difficult and hence rarely performed under field conditions. But using the 15N gas-flux method allows determining N transformation processes in their natural environment. In order to develop effective climate mitigation strategies understanding the N2O source is essential. We used the 15N gas-flux method to determine N2O and N2 emissions following grassland renewal and conversion techniques. Therefore we selected three different treatments: control (C), mechanical grassland renovation (GR) (autumn 2013) and grassland conversion to maize (GM) (spring 2014) from field plot trials on two different sites (Histic Gleysoil and Plaggic Anthrosol) near Oldenburg, Lower Saxony, Germany. We applied 15N labeled KNO3- (60 atom. % 15N) at a rate equivalent to common farming practices (150 kg N*ha-1) using needle injection of fertilizer solution in three different depths (10 cm, 15 cm, 20 cm) for homogeneous soil labeling up to 30 cm in microplots. During the first 10 days after application (May 2014) gas flux measurements from closed chambers were performed every second day and then weekly following a period of 8 weeks. Gas samples were analyzed for δ15N of N2 and N2O by IRMS according to Lewicka-Szczebak et al. (2013). Concentration and 15N enrichment of NO3- in soil water was determined on weekly samples using the SPIN-MAS technique (Stange et al. 2007). Fluxes of N2 and N2O evolved from the 15N labeled soil nitrogen pool were calculated using the equations of Spott et al. (2006). Peak events of N2 and N2O emissions occurred during the first 10 days of measurement, showing differences in soil types, as well as treatment variations. N2 fluxes up to 178 g*ha-1*day-1 and N2O fluxes up to 280 g*ha-1*day-1 were measured on the

  4. Evaluating the Impacts of Grassland Conversions to Experimental Forest on Groundwater Recharge in the Nebraska Sand Hills

    Science.gov (United States)

    Adane, Zablon A.

    The Nebraska Sand Hills grasslands provide the greatest groundwater recharge rates in the High Plains Aquifer. However, the grasslands and their ecological services have become vulnerable to land use change and degradation. This study used a series of field data to investigate the effects of grassland conversions to forest on recharge rates in a century-old experimental forest in the Sand Hills. The results show that the impact of grassland conversion on recharge was dependent on the species and plantation density. Estimated recharge rates beneath the dense plantations represent reductions of 86-94% relative to the native grassland. Results of 1H Nuclear Magnetic Resonance spectral analysis suggested that the surface soil organic carbon beneath pine plantations also contain up to 3 times the ratio of hydrophobic components than the native grasslands and may alter the soil hydraulic properties. This investigation further uncovered a previously overlooked feedback between the effect of soil organic carbon chemical shift generated by the ponderosa pine needle litter decomposition; namely that the alteration may have a link to reduced groundwater recharge rates. Thus, a global optimizer algorithm was used to estimate the effective soil hydraulic parameters from monthly soil moisture contents and recharge rates were then estimated through HYDRUS 1-D numerical modeling for grassland and pine forest soils. The impact of grassland conversion to pine was an overall reduction of groundwater recharge by nearly 100%. These outcomes highlight the significance of the grasslands for recharge, in the Sand Hills and the sustainability of the High Plains Aquifer.

  5. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California.

    Directory of Open Access Journals (Sweden)

    Jeanette K Howard

    Full Text Available The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe, created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939 are vulnerable to extinction, only 114 (6% of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%. The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to

  6. Control and eradication of endemic infectious diseases in cattle

    DEFF Research Database (Denmark)

    Houe, Hans; Nielsen, Liza Rosenbaum; Nielsen, Søren Saxmose

    "Control and eradication of endemic infectious diseases in cattle" provides the key elements that should be addressed in the establishment of bovine disease control and eradication programmes. The book aims to reach a broad group of readers, including: students; professionals in veterinary practice...... "disease profiling", which is governed by the characteristics of the agent and its interaction with the host and environment. This profile, along with due consideration of the socioeconomic circumstances, can be used to determine how best to address the problem....

  7. Mitogenomic phylogeny of cone snails endemic to Senegal.

    Science.gov (United States)

    Abalde, Samuel; Tenorio, Manuel J; Afonso, Carlos M L; Zardoya, Rafael

    2017-07-01

    Cone snails attain in Senegal one of their highest peaks of species diversity throughout the continental coast of Western Africa. A total of 15 endemic species have been described, all placed in the genus Lautoconus. While there is ample data regarding the morphology of the shell and the radular tooth of these species, virtually nothing is known regarding the genetic diversity and phylogenetic relationships of one of the most endangered groups of cones. In this work, we determined the complete or near-complete (only lacking the control region) mitochondrial (mt) genomes of 17 specimens representing 11 endemic species (Lautoconus belairensis, Lautoconus bruguieresi, Lautoconus cacao, Lautoconus cloveri, Lautoconus cf. echinophilus, Lautoconus guinaicus, Lautoconus hybridus, Lautoconus senegalensis, Lautoconus mercator, Lautoconus taslei, and Lautoconus unifasciatus). We also sequenced the complete mt genome of Lautoconus guanche from the Canary Islands, which has been related to the cones endemic to Senegal. All mt genomes share the same gene arrangement, which conforms to the consensus reported for Conidae, Neogastropoda and Caenogastropoda. Phylogenetic analyses using probabilistic methods recovered three major lineages, whose divergence coincided in time with sea level and ocean current changes as well as temperature fluctuations during the Messinian salinity crisis and the Plio-Pleistocene transition. Furthermore, the three lineages corresponded to distinct types of radular tooth (robust, small, and elongated), suggesting that dietary specialization could be an additional evolutionary driver in the diversification of the cones endemic to Senegal. The reconstructed phylogeny showed several cases of phenotypic convergence (cryptic species) and questions the validity of some species (ecotypes or phenotypic plasticity), both results having important taxonomic and conservation consequences. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Biogeographical note on Antarctic microflorae: Endemism and cosmopolitanism

    Directory of Open Access Journals (Sweden)

    Waqar Azeem Jadoon

    2013-11-01

    Full Text Available This study deals with the biogeography of Antarctic microflora (Antarctica acts as best model to study microbial biogeography such as cyanobacteria and selected halophiles with special emphasis on Halomonas variabilis and Bacillus licheniformis. Halophiles are known to be resistant not only to salt stress, but also to extreme temperature, pressure, and aridity and they are capable of surviving in harsh environments such as polar regions, deep-sea habitats, and deserts. Many microbes are known to be resistant to hostile environmental conditions, and are capable of surviving in harsh environments. Our group has isolated 444 strains belonging to 28 genera of halophiles from various environments around the world. The 16S rRNA gene sequences revealed that many of the isolated strains from geographically distant habitats having different environmental conditions, were closely related to each other, with some strains possessing 100% identical sequences. Organisms possessing survival mechanism such as spore formation are usually ubiquitous. The genus Halomonas is represented by potentially endemic strains and the ubiquitous H. variabilis, while spore-forming B. licheniformis showed cosmopolitan distribution. One potentially endemic (moderate endemicity that is regional and/or continental distribution strain was reported from Syowa station, East Antarctica, and Mario Zucchelli station, West Antarctica, which are geographically separated by 3000 km. Moreover, 15 strains having 100% similarity with B. licheniformis were considered cosmopolitans. The results of this work provide support for the middle-ground model that some microbes have moderate endemicity and others have cosmopolitan distribution. These results will contribute to a greater understanding of microbial biogeography with special emphasis on Antarctica.

  9. [Endemic situation and control progress of taeniasis in western China].

    Science.gov (United States)

    Long, Chang-Ping; Qian, Ying-Jun; Li, Tiao-Ying; Fu, Qing; Wang, Qiang; Xiao, Ning

    2014-06-01

    Taeniasis, caused by Taenia species, is one of the common zoonoses in China, particularly in the western region of China. Up to now, not enough attention has been given in the high prevalence and high burden of the diseases. In order to study the endemic patterns and control strategies of taeniasis, a series of epidemiological investigations, molecular researches and pilot control activities have been conducted in recent years. This paper reviews the relevant publications in taeniasis research over the last 10 years.

  10. Effect of soil saturation on denitrification in a grassland soil

    Directory of Open Access Journals (Sweden)

    L. M. Cardenas

    2017-10-01

    Full Text Available Nitrous oxide (N2O is of major importance as a greenhouse gas and precursor of ozone (O3 destruction in the stratosphere mostly produced in soils. The soil-emitted N2O is generally predominantly derived from denitrification and, to a smaller extent, nitrification, both processes controlled by environmental factors and their interactions, and are influenced by agricultural management. Soil water content expressed as water-filled pore space (WFPS is a major controlling factor of emissions and its interaction with compaction, has not been studied at the micropore scale. A laboratory incubation was carried out at different saturation levels for a grassland soil and emissions of N2O and N2 were measured as well as the isotopocules of N2O. We found that flux variability was larger in the less saturated soils probably due to nutrient distribution heterogeneity created from soil cracks and consequently nutrient hot spots. The results agreed with denitrification as the main source of fluxes at the highest saturations, but nitrification could have occurred at the lower saturation, even though moisture was still high (71 % WFSP. The isotopocules data indicated isotopic similarities in the wettest treatments vs. the two drier ones. The results agreed with previous findings where it is clear there are two N pools with different dynamics: added N producing intense denitrification vs. soil N resulting in less isotopic fractionation.

  11. Plutonium in a grassland ecosystem. [Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    Little, C.A.

    1976-08-01

    A study was made of plutonium contamination of grassland at the Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geographical areas; whether or not the predominant isotopes, /sup 238/Pu and /sup 239/Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for Pu analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99 percent of the total plutonium was contained in the soil and the concentrations were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes.

  12. Metacommunity analysis of amoeboid protists in grassland soils.

    Science.gov (United States)

    Fiore-Donno, Anna Maria; Weinert, Jan; Wubet, Tesfaye; Bonkowski, Michael

    2016-01-11

    This study reveals the diversity and distribution of two major ubiquitous groups of soil amoebae, the genus Acanthamoeba and the Myxomycetes (plasmodial slime-moulds) that are rarely, if ever, recovered in environmental sampling studies. We analyzed 150 grassland soil samples from three Biodiversity Exploratories study regions in Germany. We developed specific primers targeting the V2 variable region in the first part of the small subunit of the ribosomal RNA gene for high-throughput pyrotag sequencing. From ca. 1 million reads, applying very stringent filtering and clustering parameters to avoid overestimation of the diversity, we obtained 273 acanthamoebal and 338 myxomycete operational taxonomic units (OTUs, 96% similarity threshold). This number is consistent with the genetic diversity known in the two investigated lineages, but unequalled to date by any environmental sampling study. Only very few OTUs were identical to already known sequences. Strikingly different OTUs assemblages were found between the three German regions (PerMANOVA p.value = 0.001) and even between sites of the same region (multiple-site Simpson-based similarity indices <0.4), showing steep biogeographical gradients.

  13. Soil invertebrate fauna enhances grassland succession and diversity.

    Science.gov (United States)

    De Deyn, Gerlinde B; Raaijmakers, Ciska E; Zoomer, H Rik; Berg, Matty P; de Ruiter, Peter C; Verhoef, Herman A; Bezemer, T Martijn; van der Putten, Wim H

    2003-04-17

    One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation. Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores. More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein. However, the influence of invertebrate soil fauna on succession has so far received little attention. Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity. Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages. Soil fauna from the mid-succession stage had the strongest effect. Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity.

  14. The nutritive value of Valjevac grassland - Zasavica reservation

    Directory of Open Access Journals (Sweden)

    Grdović Svetlana

    2013-01-01

    Full Text Available Valjevac pasture of Zasavica reservation with its area of 300 ha presents a significant area for grazing cattle. In order to evaluate its potential for livestock production, the botanical and chemical composition of hay in three different time periods was observed (spring, summer and autumn. The determined plants species confirmed the richness of Zasavica grasslands, as well as the presence of dry, moist and forest habitat plants. The analyzed plants mostly belong to the Poaceae, Fabaceae, Asteraceae and Plantaginaceae families. Chemical analysis determined that the protein content decreased (P<0.01 from April (17.22±0.40 % to October (10.30±0.16 %, and cellulose content increased (P<0.01 (from 19.07±0.38 % in April to 21.65±0.41 % in October. The calculated energy density of hay samples ranged from 0.425 Starch Units (SU in October, 0.443 SU in April to 0.448 SU in June. The Valjevac pasture with its numerous plant species is of great importance in upkeeping biodiversity and also presents a solid base for livestock production. The determined levels of manganese and copper point out to the need of copper supplementation especially during the late summer and autumn periods. [Projekat Ministarstva nauke Republike Srbije, br. III46002

  15. Improvement of native grassland by legumes introduction and tillage techniques

    Directory of Open Access Journals (Sweden)

    Syamsu Bahar

    1999-10-01

    Full Text Available A factorial design using three species of legumes (Siratro, Centro and Stylo and three different of tillage techniques (no-tillage, minimum tillage and total tillage was applied in this experiment. The results showed that there was no interaction between species and tillage techniques. There was significant reductions on bulk density from 1.23±0.03 g/cm3 (no-tillage to 1.07±0.02 g/cm3 (minimum tillage and 1.05±0.03 g/cm3 (total tillage. Also reductions on penetration resistance from 17.47±3.84 kg/cm2 (no-tillage to 3.31±0.43 kg/cm2 (minimum tillage and 3.19±0.45 kg/cm2 (total tillage. Otherwise significant increasing on aeration porosity from 12.80±0.80% vol. (no-tillage to 21.70±0.95% vol. (minimum tillage and 20.70±0.35% vol. (total tillage. Total tillage gives increased dry matter yield. Also both total tillage and minimum tillage give yields with a higher percentage of legumes compared with no-tillage. It was concluded that total tillage and minimum tillage could be used for improving native grassland.

  16. Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions

    Science.gov (United States)

    Allison, S. D.; Jastrow, J. D.

    2004-12-01

    Extracellular enzymes are necessary to degrade complex organic compounds present in soils. Using physical fractionation procedures, we tested whether old soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microaggregates, and the clay fraction, which contains carbon with a mean residence time of ~200 years. The activities of two cellulose-degrading enzymes and a chitin-degrading enzyme were 2-10 times greater in organic matter fractions than in bulk soil, consistent with the rapid turnover of these fractions. Polyphenol oxidase activity was 3 times greater in the clay fraction than in the bulk soil, despite very slow carbon turnover in this fraction. Changes in enzyme activity across the restoration chronosequence were small once adjusted for increases in soil carbon concentration, although polyphenol oxidase activity per unit carbon declined by 50% in native prairie versus cultivated soil. These results are consistent with a `two-pool' model of enzyme and carbon turnover in grassland soils. In light organic matter fractions, enzyme production and carbon turnover both occur rapidly. However, in mineral-dominated fractions, both enzymes and their carbon substrates are immobilized on mineral surfaces, leading to slow turnover. Soil carbon accumulation in the clay fraction and across the prairie restoration chronosequence probably reflects increasing physical isolation of enzymes and substrates on the molecular scale, rather than the micron to millimeter scale.

  17. Seasonal methane dynamics in three temperate grasslands on peat

    DEFF Research Database (Denmark)

    Schäfer, Carolyn; Elsgaard, Lars; Hoffmann, Carl Christian

    2012-01-01

    Background and Aims Drained peatlands are considered to be insignificant CH4 sources, but the effect of drainage on CH4 dynamics has not been extensively studied. We investigated seasonal dynamics of CH4 in two fen peat soils and one bog peat soil under permanent grassland in Denmark. Methods Soil......, even though soil CH4 concentrations of up to 155 and 1000 μmol CH4 dm−3 were measured in one of the fen peats and in the bog peat, respectively. Significant CH4 concentrations were observed above the water table. Methane production assays confirmed the presence of viable methanogens in the upper parts...... of the bog peat soil. The aerenchymous plant Juncus effusus L. liberated CH4 from the peat at rates of up to 3.3 mg CH4 m−2 h−1. No CH4 dynamics were observed in the second fen peat which, in contrast to the other two sites, had high sulfate concentrations. Conclusions Peat type and the distribution...

  18. Analysis of the production stability of mixed grasslands. II. A mathematical framework for the quantification of production stability of grassland ecosystems

    NARCIS (Netherlands)

    Schulte, R.P.O.

    2003-01-01

    The analysis of the intrinsic properties and processes of ecosystems, which regulate the production stability of mixed grasslands, has been complicated by the environmental noise caused by stochastic weather fluctuations. A mathematical framework is presented to deduct the actual, the extrinsic and

  19. Changing patterns of basic household consumption in the Inner Mongolian grasslands: a case study of policy-oriented adoptive changes in the use of grasslands

    NARCIS (Netherlands)

    Du, B.; Zhen, L.; Groot, de R.S.; Goulden, C.E.; Long, X.; Cao, X.; Wu, R.; Sun, C.

    2014-01-01

    Grassland ecosystems, as the basic natural resources in the Inner Mongolia Autonomous Region, are becoming increasingly sensitive to human intervention, leading to deterioration in fragile ecosystems. The goal of this study was to describe the restoration policy-oriented adoptive changes to basic

  20. Evolution of endemism on a young tropical mountain.

    Science.gov (United States)

    Merckx, Vincent S F T; Hendriks, Kasper P; Beentjes, Kevin K; Mennes, Constantijn B; Becking, Leontine E; Peijnenburg, Katja T C A; Afendy, Aqilah; Arumugam, Nivaarani; de Boer, Hugo; Biun, Alim; Buang, Matsain M; Chen, Ping-Ping; Chung, Arthur Y C; Dow, Rory; Feijen, Frida A A; Feijen, Hans; Feijen-van Soest, Cobi; Geml, József; Geurts, René; Gravendeel, Barbara; Hovenkamp, Peter; Imbun, Paul; Ipor, Isa; Janssens, Steven B; Jocqué, Merlijn; Kappes, Heike; Khoo, Eyen; Koomen, Peter; Lens, Frederic; Majapun, Richard J; Morgado, Luis N; Neupane, Suman; Nieser, Nico; Pereira, Joan T; Rahman, Homathevi; Sabran, Suzana; Sawang, Anati; Schwallier, Rachel M; Shim, Phyau-Soon; Smit, Harry; Sol, Nicolien; Spait, Maipul; Stech, Michael; Stokvis, Frank; Sugau, John B; Suleiman, Monica; Sumail, Sukaibin; Thomas, Daniel C; van Tol, Jan; Tuh, Fred Y Y; Yahya, Bakhtiar E; Nais, Jamili; Repin, Rimi; Lakim, Maklarin; Schilthuizen, Menno

    2015-08-20

    Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it is debated whether mountain endemics mostly originate from local lowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere. Here we investigate the evolutionary routes to endemism by sampling an entire tropical mountain biota on the 4,095-metre-high Mount Kinabalu in Sabah, East Malaysia. We discover that most of its unique biodiversity is younger than the mountain itself (6 million years), and comprises a mix of immigrant pre-adapted lineages and descendants from local lowland ancestors, although substantial shifts from lower to higher vegetation zones in this latter group were rare. These insights could improve forecasts of the likelihood of extinction and 'evolutionary rescue' in montane biodiversity hot spots under climate change scenarios.

  1. Recovery of endemic dragonflies after removal of invasive alien trees.

    Science.gov (United States)

    Samways, Michael J; Sharratt, Norma J

    2010-02-01

    Because dragonflies are very sensitive to alien trees, we assessed their response to large-scale restoration of riparian corridors. We compared three types of disturbance regime--alien invaded, cleared of alien vegetation, and natural vegetation (control)--and recorded data on 22 environmental variables. The most significant variables in determining dragonfly assemblages were percentage of bank cover and tree canopy cover, which indicates the importance of vegetation architecture for these dragonflies. This finding suggests that it is important to restore appropriate marginal vegetation and sunlight conditions. Recovery of dragonfly assemblages after the clearing of alien trees was substantial. Species richness and abundance at restored sites matched those at control sites. Dragonfly assemblage patterns reflected vegetation succession. Thus, initially eurytopic, widespread species were the main beneficiaries of the removal of alien trees, and stenotopic, endemic species appeared after indigenous vegetation recovered over time. Important indicator species were the two national endemics (Allocnemis leucosticta and Pseudagrion furcigerum), which, along with vegetation type, can be used to monitor return of overall integrity of riparian ecology and to make management decisions. Endemic species as a whole responded positively to restoration, which suggests that indigenous vegetation recovery has major benefits for irreplaceable and widespread generalist species.

  2. [Diversity and distribution of grasshoppers (Orthoptera: Acridoidea) in grasslands of the Southern Pampas region, Argentina].

    Science.gov (United States)

    Mariottini, Yanina; De Wysiecki, María Laura; Lange, Carlos Ernesto

    2013-03-01

    In Argentina, the grasslands of Pampas region comprise approximately 15% of the country. As in other grasslands of the world, grasshoppers are among the most important native herbivores. Their economic importance has been recognized in Argentina since the mid to late nineteenth century, since outbreaks of different species have become recurrent phenomena. Therefore, the main objective of this work was to study their diversity and distribution in grasslands of the Southern Pampas region (Laprida county, Buenos Aires province), as one of the most affected areas. The study was conducted during five seasons (2005-10). Sampling sites were represented by the most common plant communities in this area, classified in four categories: native grasslands, disturbed grasslands, implanted pastures and halophilous grasslands. The samplings were conducted from mid-spring to early autumn, with five or six samples per season. We estimated the following population descriptors: species richness (S), eveness (E), dominance (J), and diversity index (H'). In order to evaluate the similitude of the grasshopper communities present in the different plant communities, we used qualitative and quantitative coefficients of similitude. A total of 22 species of grasshoppers were collected, of which 21 belong to the family Acrididae. The subfamily Melanoplinae was the most diverse with eight species. The largest species richness was recorded in native grasslands (18). The different communities of grasshoppers had similar indices of evenness and dominance (p>0.05). Considering all plant communities, the average value of Shannon-Wiener index was 1.58+/-0.075. There was a positive correlation between evenness index and species richness (pgrasshoppers species richness, and diversity of grasshoppers. According to the qualitative indices applied, the similitude between different grasshopper communities was higher than 60%. In general, the species that had a higher frequency of occurrence showed greater

  3. Drought and Carbon Cycling of Grassland Ecosystems under Global Change: A Review

    Directory of Open Access Journals (Sweden)

    Tianjie Lei

    2016-10-01

    Full Text Available In recent years, the increased intensity and duration of droughts have dramatically altered the structure and function of grassland ecosystems, which have been forced to adapt to this change in climate. Combinations of global change drivers such as elevated atmospheric CO2 concentration, warming, nitrogen (N deposition, grazing, and land-use change have influenced the impact that droughts have on grassland C cycling. This influence, to some extent, can modify the relationship between droughts and grassland carbon (C cycling in the multi-factor world. Unfortunately, prior reviews have been primarily anecdotal from the 1930s to the 2010s. We investigated the current state of the study on the interactive impacts of multiple factors under drought scenarios in grassland C cycling and provided scientific advice for dealing with droughts and managing grassland C cycling in a multi-factor world. Currently, adequate information is not available on the interaction between droughts and global change drivers, which would advance our understanding of grassland C cycling responses. It was determined that future experiments and models should specifically test how droughts regulate grassland C cycling under global changes. Previous multi-factor experiments of current and future global change conditions have studied various drought scenarios poorly, including changes in precipitation frequency and amplitude, timing, and interactions with other global change drivers. Multi-factor experiments have contributed to quantifying these potential changes and have provided important information on how water affects ecosystem processes under global change. There is an urgent need to establish a systematic framework that can assess ecosystem dynamic responses to droughts under current and future global change and human activity, with a focus on the combined effects of droughts, global change drivers, and the corresponding hierarchical responses of an ecosystem.

  4. Vegetation in clear-cuts depends on previous land use: a century-old grassland legacy

    Science.gov (United States)

    Jonason, Dennis; Ibbe, Mathias; Milberg, Per; Tunér, Albert; Westerberg, Lars; Bergman, Karl-Olof

    2014-01-01

    Plant species richness in central and northern European seminatural grasslands is often more closely linked to past than present habitat configuration, which is indicative of an extinction debt. In this study, we investigate whether signs of historical grassland management can be found in clear-cuts after at least 80 years as coniferous production forest by comparing floras between clear-cuts with a history as meadow and as forest in the 1870s in Sweden. Study sites were selected using old land-use maps and data on present-day clear-cuts. Species traits reflecting high capacities for dispersal and persistence were used to explain any possible links between the plants and the historical land use. Clear-cuts that were formerly meadow had, on average, 36% higher species richness and 35% higher richness of grassland indicator species, as well as a larger overall seed mass and lower anemochory, compared to clear-cuts with history as forest. We suggest that the plants in former meadows never disappeared after afforestation but survived as remnant populations. Many contemporary forests in Sweden were managed as grasslands in the 1800s. As conservation of remaining grassland fragments will not be enough to reduce the existing extinction debts of the flora, these young forests offer opportunities for grassland restoration at large scales. Our study supports the concept of remnant populations and highlights the importance of considering historical land use for understanding the distribution of grassland plant species in fragmented landscapes, as well as for policy-making and conservation. PMID:25540690

  5. The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

    Science.gov (United States)

    Davis, Stacy C.; Burkle, Laura A.; Cross, Wyatt F.; Cutting, Kyle A.

    2014-01-01

    Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season. PMID:25338008

  6. Grassland to shrubland state transitions enhance carbon sequestration in the northern Chihuahuan Desert.

    Science.gov (United States)

    Petrie, M D; Collins, S L; Swann, A M; Ford, P L; Litvak, M E

    2015-03-01

    The replacement of native C4 -dominated grassland by C3 -dominated shrubland is considered an ecological state transition where different ecological communities can exist under similar environmental conditions. These state transitions are occurring globally, and may be exacerbated by climate change. One consequence of the global increase in woody vegetation may be enhanced ecosystem carbon sequestration, although the responses of arid and semiarid ecosystems may be highly variable. During a drier than average period from 2007 to 2011 in the northern Chihuahuan Desert, we found established shrubland to sequester 49 g C m(-2) yr(-1) on average, while nearby native C4 grassland was a net source of 31 g C m(-2) yr(-1) over this same period. Differences in C exchange between these ecosystems were pronounced--grassland had similar productivity compared to shrubland but experienced higher C efflux via ecosystem respiration, while shrubland was a consistent C sink because of a longer growing season and lower ecosystem respiration. At daily timescales, rates of carbon exchange were more sensitive to soil moisture variation in grassland than shrubland, such that grassland had a net uptake of C when wet but lost C when dry. Thus, even under unfavorable, drier than average climate conditions, the state transition from grassland to shrubland resulted in a substantial increase in terrestrial C sequestration. These results illustrate the inherent tradeoffs in quantifying ecosystem services that result from ecological state transitions, such as shrub encroachment. In this case, the deleterious changes to ecosystem services often linked to grassland to shrubland state transitions may at least be partially offset by increased ecosystem carbon sequestration. © 2014 John Wiley & Sons Ltd.

  7. Using Calibrated RGB Imagery from Low-Cost Uavs for Grassland Monitoring: Case Study at the Rengen Grassland Experiment (rge), Germany

    Science.gov (United States)

    Lussem, U.; Hollberg, J.; Menne, J.; Schellberg, J.; Bareth, G.

    2017-08-01

    Monitoring the spectral response of intensively managed grassland throughout the growing season allows optimizing fertilizer inputs by monitoring plant growth. For example, site-specific fertilizer application as part of precision agriculture (PA) management requires information within short time. But, this requires field-based measurements with hyper- or multispectral sensors, which may not be feasible on a day to day farming practice. Exploiting the information of RGB images from consumer grade cameras mounted on unmanned aerial vehicles (UAV) can offer cost-efficient as well as near-real time analysis of grasslands with high temporal and spatial resolution. The potential of RGB imagery-based vegetation indices (VI) from consumer grade cameras mounted on UAVs has been explored recently in several. However, for multitemporal analyses it is desirable to calibrate the digital numbers (DN) of RGB-images to physical units. In this study, we explored the comparability of the RGBVI from a consumer grade camera mounted on a low-cost UAV to well established vegetation indices from hyperspectral field measurements for applications in grassland. The study was conducted in 2014 on the Rengen Grassland Experiment (RGE) in Germany. Image DN values were calibrated into reflectance by using the Empirical Line Method (Smith & Milton 1999). Depending on sampling date and VI the correlation between the UAV-based RGBVI and VIs such as the NDVI resulted in varying R2 values from no correlation to up to 0.9. These results indicate, that calibrated RGB-based VIs have the potential to support or substitute hyperspectral field measurements to facilitate management decisions on grasslands.

  8. USING CALIBRATED RGB IMAGERY FROM LOW-COST UAVS FOR GRASSLAND MONITORING: CASE STUDY AT THE RENGEN GRASSLAND EXPERIMENT (RGE, GERMANY

    Directory of Open Access Journals (Sweden)

    U. Lussem

    2017-08-01

    Full Text Available Monitoring the spectral response of intensively managed grassland throughout the growing season allows optimizing fertilizer inputs by monitoring plant growth. For example, site-specific fertilizer application as part of precision agriculture (PA management requires information within short time. But, this requires field-based measurements with hyper- or multispectral sensors, which may not be feasible on a day to day farming practice. Exploiting the information of RGB images from consumer grade cameras mounted on unmanned aerial vehicles (UAV can offer cost-efficient as well as near-real time analysis of grasslands with high temporal and spatial resolution. The potential of RGB imagery-based vegetation indices (VI from consumer grade cameras mounted on UAVs has been explored recently in several. However, for multitemporal analyses it is desirable to calibrate the digital numbers (DN of RGB-images to physical units. In this study, we explored the comparability of the RGBVI from a consumer grade camera mounted on a low-cost UAV to well established vegetation indices from hyperspectral field measurements for applications in grassland. The study was conducted in 2014 on the Rengen Grassland Experiment (RGE in Germany. Image DN values were calibrated into reflectance by using the Empirical Line Method (Smith & Milton 1999. Depending on sampling date and VI the correlation between the UAV-based RGBVI and VIs such as the NDVI resulted in varying R2 values from no correlation to up to 0.9. These results indicate, that calibrated RGB-based VIs have the potential to support or substitute hyperspectral field measurements to facilitate management decisions on grasslands.

  9. Composition, Endemism and Phytogeographical Affinities of the Taiwan Flora

    Directory of Open Access Journals (Sweden)

    Chang-Fu Hsieh

    2002-12-01

    Full Text Available The Taiwan vascular flora is exceptionally interesting not only because it is rich and diversified, but because it is of great phytogeographic significance owing to its geographic location. The flora of Taiwan, including naturalized plants, comprises 233 families and 1389 genera with 4216 species. In terms of major growth forms, there are 588 trees, 426 shrubs, 249 lianas, 177 vines, and 2776 herbs or ferns. Approximately 234 species are exotics typically associated with pastures, road clearings and other human disturbances. An extremely large percentage of these naturalized plants are of tropical New World origin. Among the native flora, the Orchidaceae (331 species, Gramineae (249, Compositae (194, Leguminosae (176, Cyperaceae (174, Rosaceae (105, Rubiaceae (93 and Euphorbiaceae (76 rank highest in numbers of species. Clearly, the greatest part of Taiwan's floristics richness comes from a wealth of species in primarily lowland (0–600 m asl. taxa. A total of 2571 species were recorded in the lowlands, whereas only about 251 species occur between 3100-3950 m. Endemic genera are extremely scarce in Taiwan, with only four, namely Sinopanax (Araliaceae, Hayatella (Rubiaceae, Kudoacanthus (Acanthaceae, and Haraella (Orchidaceae. In contrast to the low percentage of generic endemism, there is a remarkably higher specific endemism. About 1041 species (26.1% of indigenous plants are known only from Taiwan. A detailed examination of these species shows that there is a distinct trend of increasing endemism with increasing altitude (r² = 0.99. A survey of indigenous non-endemic species on the basis of their geographical distribution outside Taiwan shows that they can be classified into 6 major categories: 1. pantropical and palaeotropical species (1029 species; 2. species distributed in eastern Asia, from Himalayas through southern & eastern China to Taiwan, with some extending to the Ryukyus and Japan (1075 species; 3. widespread species extending

  10. Quantifying nitrous oxide emissions from Chinese grasslands with a process-based model

    Directory of Open Access Journals (Sweden)

    F. Zhang

    2010-06-01

    Full Text Available As one of the largest land cover types, grassland can potentially play an important role in the ecosystem services of natural resources in China. Nitrous oxide (N2O is a major greenhouse gas emitted from grasslands. Current N2O inventory at a regional or national level in China relies on the emission factor method, which is based on limited measurements. To improve the accuracy of the inventory by capturing the spatial variability of N2O emissions under the diverse climate, soil and management conditions across China, we adopted an approach by utilizing a process-based biogeochemical model, DeNitrification-DeComposition (DNDC, to quantify N2O emissions from Chinese grasslands. In the present study, DNDC was tested against datasets of N2O fluxes measured at eight grassland sites in China with encouraging results. The validated DNDC was then linked to a GIS database holding spatially differentiated information of climate, soil, vegetation and management at county-level for all the grasslands in the country. Daily weather data for 2000–2007 from 670 meteorological stations across the entire domain were employed to serve the simulations. The modelled results on a national scale showed a clear geographic pattern of N2O emissions. A high-emission strip showed up stretching from northeast to central China, which is consistent with the eastern boundary between the temperate grassland region and the major agricultural regions of China. The grasslands in the western mountain regions, however, emitted much less N2O. The regionally averaged rates of N2O emissions were 0.26, 0.14 and 0.38 kg nitrogen (N ha−1 y−1 for the temperate, montane and tropical/subtropical grasslands, respectively. The annual mean N2O emission from the total 337 million ha of grasslands in China was 76.5 ± 12.8 Gg N for the simulated years.

  11. A Satellite-Based Model for Simulating Ecosystem Respiration in the Tibetan and Inner Mongolian Grasslands

    Directory of Open Access Journals (Sweden)

    Rong Ge

    2018-01-01

    Full Text Available It is important to accurately evaluate ecosystem respiration (RE in the alpine grasslands of the Tibetan Plateau and the temperate grasslands of the Inner Mongolian Plateau, as it serves as a sensitivity indicator of regional and global carbon cycles. Here, we combined flux measurements taken between 2003 and 2013 from 16 grassland sites across northern China and the corresponding MODIS land surface temperature (LST, enhanced vegetation index (EVI, and land surface water index (LSWI to build a satellite-based model to estimate RE at a regional scale. First, the dependencies of both spatial and temporal variations of RE on these biotic and climatic factors were examined explicitly. We found that plant productivity and moisture, but not temperature, can best explain the spatial pattern of RE in northern China’s grasslands; while temperature plays a major role in regulating the temporal variability of RE in the alpine grasslands, and moisture is equally as important as temperature in the temperate grasslands. However, the moisture effect on RE and the explicit representation of spatial variation process are often lacking in most of the existing satellite-based RE models. On this basis, we developed a model by comprehensively considering moisture, temperature, and productivity effects on both temporal and spatial processes of RE, and then, we evaluated the model performance. Our results showed that the model well explained the observed RE in both the alpine (R2 = 0.79, RMSE = 0.77 g C m−2 day−1 and temperate grasslands (R2 = 0.75, RMSE = 0.60 g C m−2 day−1. The inclusion of the LSWI as the water-limiting factor substantially improved the model performance in arid and semi-arid ecosystems, and the spatialized basal respiration rate as an indicator for spatial variation largely determined the regional pattern of RE. Finally, the model accurately reproduced the seasonal and inter-annual variations and spatial variability of RE, and it avoided

  12. No Significant Changes in Topsoil Carbon in the Grasslands of Northern China Between the 1980s and 2000s

    Science.gov (United States)

    Liu, S.; Yang, Y.; Shen, H.; Hu, H.; Zhao, X.; Li, H.; Liu, T.; Fang, J.

    2017-12-01

    The grasslands of northern China store a large amount of soil organic carbon (SOC), and the small changes in SOC stock could significantly affect the regional C cycle. However, recent estimates of SOC changes in this region are highly controversial. In this study, we examined and mapped the changes in the SOC density (SOCD) in the upper 30 cm of the grasslands of northern China between the 1980s and 2000s, using an improved approach that integrates field-based measurements into machine learning algorithms (artificial neural network and random forest). The random forest-generated SOCD averaged 5.55 kg C m-2 in the 1980s and 5.53 kg C m-2 in the 2000s. The change ranged between -0.17 and 0.22 kg C m-2 at the 95% confidence level, suggesting that the overall SOCD did not change significantly during the study period. However, the change in SOCD exhibited large regional variability. The topsoil of the Inner Mongolian grasslands experienced a significant C loss (4.86 vs. 4.33 kg C m-2), whereas that of the Xinjiang grasslands exhibited an accumulation of C (5.55 vs. 6.46 kg C m-2). In addition, the topsoil C in the Tibetan alpine grasslands remained relatively stable (6.12 vs. 6.06 kg C m-2). A comparison of different grassland types indicated that SOCD exhibited significant decreases in typical steppe, whereas showed increases in mountain meadow, and were stable in the remaining grasslands (alpine meadow, alpine steppe, mountain steppe and desert steppe). Climate variables were shown to be the main determines of the change of SOCD. Increases in precipitation could lead to SOC increase in temperate grasslands and SOC loss in alpine grasslands, while climate warming is likely to cause SOC loss in temperate grasslands. Overall, our study shows that northern grasslands in China remained a neutral SOC sink between the 1980s and 2000s.

  13. Evaporation from Pinus caribaea plantations on former grassland soils under maritime tropical conditions

    Science.gov (United States)

    Waterloo, M. J.; Bruijnzeel, L. A.; Vugts, H. F.; Rawaqa, T. T.

    1999-07-01

    Wet canopy and dry canopy evaporation from young and mature plantations of Pinus caribaea on former grassland soils under maritime tropical conditions in southwestern Viti Levu, Fiji, were determined using micrometeorological and hydrological techniques. Modeled annual evaporation totals (ET) of 1926 and 1717 mm were derived for the 6- and the 15-year-old stands, respectively. Transpiration made up 72% and 70% of annual ET, and modeled rainfall interception by the trees and litter layer was 20-22% and 8-9% in the young and the mature stands respectively. Monthly ET was related to forest leaf area index and was much higher than that for the kind of tall fire-climax Pennisetum polystachyon grassland replaced by the forests. Grassland reforestation resulted in a maximum decrease in annual water yield of 1180 mm on a plot basis, although it is argued that a reduction of (at least) 500-700 mm would be more realistic at the catchment scale. The impact of reforesting grassland on the water resources in southwest Viti Levu is enhanced by its location in a maritime, seasonal climate in the outer tropics, which favors a larger difference between annual forest and grassland evaporation totals than do equatorial regions.

  14. Grassland communities in the USA and expected trends associated with climate change

    Directory of Open Access Journals (Sweden)

    David Paul Belesky

    2016-06-01

    Full Text Available Grasslands, including managed grazinglands, represent one of the largest ecosystems on the planet. Managed grazinglands in particular tend to occupy marginal climatic and edaphic resource zones, thus exacerbating responses in net primary productivity relative to changes in system resources, including anthropogenic factors. Climate dynamism, as evident from the fossil record, appears to be a putative feature of our planet. Recent global trends in temperature and precipitation patterns seem to differ from long-term patterns and have been associated with human activities linked with increased greenhouse gas emissions; specifically CO2. Thus grasslands, with their diverse floristic components, and interaction with and dependence upon herbivores, have a remarkable ability to persist and sustain productivity in response to changing resource conditions. This resistance and resilience to change, including uncertain long-term weather conditions, establishes managed grasslands as an important means of protecting food security. We review responses of grassland communities across regions of the USA and consider the responses in productivity and system function with respect to climatic variation. Research is needed to identify plant resources and management technologies that strengthen our ability to capitalize upon physiological and anatomical features prevalent in grassland communities associated with varying growing conditions.

  15. FLORISTIC CHANGES ALONG THE TOPOGRAPHICAL GRADIENT IN MONTANE GRASSLANDS IN MONTI PICENTINI (CAMPANIA, SW ITALY

    Directory of Open Access Journals (Sweden)

    M. CUTINI

    2010-01-01

    Full Text Available Populations of xerotolerant species (Achnatherum calamagrostis, Stipa crassiculmis subsp. picentina, are scattered along a wide altitudinal gradient on slopes at mid- and high elevation in Monti Picentini, a subcoastal mesozoic limestone ridge in Tyrrhenian Southern Italy. Their stands are widespread in grasslands of mostly secondary origin. At lower altitudes these grasslands replace former deciduous forest communities dominated by oaks or beech, while at higher altitudes they reach the summits, where they apparently merge into the remnants of the still partially grazed, zonal climatogenic, grasslands ranging above the local tree-line. Nevertheless primary stands of these grasslands are to be found around the many clusters of highly dynamic sites of the montane and sub-alpine levels, scattered around screes and rocky outcrops of the prevalently dolomitic morphology of the slopes. This virtual continuity of non arboreal communities across more than 1000 metres of the local topographical gradient, where azonal, relic stands of Pinus nigra s.l. are transitional between the grasslands and the surrounding zonal broadleaved forest vegetation, stresses patterns of the coenological changes between Festuco-Brometea and Elyno-Seslerietea along the catena, which suggest fragmentary persistence of a paleozonation.

  16. FLORISTIC CHANGES ALONG THE TOPOGRAPHICAL GRADIENT IN MONTANE GRASSLANDS IN MONTI PICENTINI (CAMPANIA, SW ITALY

    Directory of Open Access Journals (Sweden)

    F. SPADA

    2010-04-01

    Full Text Available Populations of xerotolerant species (Achnatherum calamagrostis, Stipa crassiculmis subsp. picentina, are scattered along a wide altitudinal gradient on slopes at mid- and high elevation in Monti Picentini, a subcoastal mesozoic limestone ridge in Tyrrhenian Southern Italy. Their stands are widespread in grasslands of mostly secondary origin. At lower altitudes these grasslands replace former deciduous forest communities dominated by oaks or beech, while at higher altitudes they reach the summits, where they apparently merge into the remnants of the still partially grazed, zonal climatogenic, grasslands ranging above the local tree-line. Nevertheless primary stands of these grasslands are to be found around the many clusters of highly dynamic sites of the montane and sub-alpine levels, scattered around screes and rocky outcrops of the prevalently dolomitic morphology of the slopes. This virtual continuity of non arboreal communities across more than 1000 metres of the local topographical gradient, where azonal, relic stands of Pinus nigra s.l. are transitional between the grasslands and the surrounding zonal broadleaved forest vegetation, stresses patterns of the coenological changes between Festuco-Brometea and Elyno-Seslerietea along the catena, which suggest fragmentary persistence of a paleozonation.

  17. Breeding Biology of Grassland Birds in Western New York: Conservation and Management Implications

    Directory of Open Access Journals (Sweden)

    Christopher J. Norment

    2010-12-01

    Full Text Available Declining grassland breeding bird populations have led to increased efforts to assess habitat quality, typically by estimating density or relative abundance. Because some grassland habitats may function as ecological traps, a more appropriate metric for determining quality may be breeding success. Between 1994 and 2003 we gathered data on the nest fates of Eastern Meadowlarks (Sturnella magna, Bobolinks (Dolichonyx oryzivorous, and Savannah Sparrows (Passerculus sandwichensis in a series of fallow fields and pastures/hayfields in western New York State. We calculated daily survival probabilities using the Mayfield method, and used the logistic-exposure method to model effects of predictor variables on nest success. Nest survival probabilities were 0.464 for Eastern Meadowlarks (n = 26, 0.483 for Bobolinks (n = 91, and 0.585 for Savannah Sparrows (n = 152. Fledge dates for first clutches ranged between 14 June and 23 July. Only one obligate grassland bird nest was parasitized by Brown-headed Cowbirds (Molothrus ater, for an overall brood parasitism rate of 0.004. Logistic-exposure models indicated that daily nest survival probabilities were higher in pastures/hayfields than in fallow fields. Our results, and those from other studies in the Northeast, suggest that properly managed cool season grassland habitats in the region may not act as ecological traps, and that obligate grassland birds in the region may have greater nest survival probabilities, and lower rates of Brown-headed Cowbird parasitism, than in many parts of the Midwest.

  18. Woody plant encroachment of grasslands: a comparison of terrestrial and wetland settings.

    Science.gov (United States)

    Saintilan, Neil; Rogers, Kerrylee

    2015-02-01

    A global trend of woody plant encroachment of terrestrial grasslands is co-incident with woody plant encroachment of wetland in freshwater and saline intertidal settings. There are several arguments for considering tree encroachment of wetlands in the context of woody shrub encroachment of grassland biomes. In both cases, delimitation of woody shrubs at regional scales is set by temperature thresholds for poleward extent, and by aridity within temperature limits. Latitudinal expansion has been observed for terrestrial woody shrubs and mangroves, following recent warming, but most expansion and thickening has been due to the occupation of previously water-limited grassland/saltmarsh environments. Increases in atmospheric CO₂, may facilitate the recruitment of trees in terrestrial and wetland settings. Improved water relations, a mechanism that would predict higher soil moisture in grasslands and saltmarshes, and also an enhanced capacity to survive arid conditions, reinforces local mechanisms of change. The expansion of woody shrubs and mangroves provides a negative feedback on elevated atmospheric CO₂ by increasing carbon sequestration in grassland and saltmarsh, and is a significant carbon sink globally. These broad-scale vegetation shifts may represent a new stable state, reinforced by positive feedbacks between global change drivers and endogenic mechanisms of persistence in the landscape.

  19. Shift in soil microbial communities with shrub encroachment in Inner Mongolia grasslands, China

    Science.gov (United States)

    Shen, H.; Li, H.; Zhang, J.; Hu, H.; Chen, L.; Zhu, Y.; Fang, J.

    2017-12-01

    The ongoing expansion of shrub encroachment into grasslands represents a unique form of land cover change. How this process affects soil microbial communities is poorly understood. In this study, we aim to assess the effects of shrub encroachment on soil microbial biomass, abundance and composition by comparing data between shrub patches and neighboring herb patches in shrub-encroached grasslands (SEGs) in Inner Mongolia, China. Fourteen SEG sites from two ecosystem types (typical and desert grasslands) were investigated. The phospholipid fatty acid (PLFA) method was used to analyze the composition and biomass of the soil microbial community. Our results showed that the top-soil microbial biomass and abundances of gram-negative bacteria, arbuscular mycorrhizal fungi, and actinomycetes were significantly higher in shrub patches than in herb patches in both typical and desert grasslands (P fungi to bacteria ratio was significantly higher in shrub patches than in herb patches in desert grassland (P soil microbial communities, which makes the microbial communities toward a fresh organic carbon-based structure. This study highlights the importance of edaphic and climate factors in microbial community shifts in SEGs.

  20. Air quality and human health impacts of grasslands and shrublands in the United States

    Science.gov (United States)

    Gopalakrishnan, Varsha; Hirabayashi, Satoshi; Ziv, Guy; Bakshi, Bhavik R.

    2018-06-01

    Vegetation including canopy, grasslands, and shrublands can directly sequester pollutants onto the plant surface, resulting in an improvement in air quality. Until now, several studies have estimated the pollution removal capacity of canopy cover at the level of a county, but no such work exists for grasslands and shrublands. This work quantifies the air pollution removal capacity of grasslands and shrublands at the county-level in the United States and estimates the human health benefits associated with pollution removal using the i-Tree Eco model. Sequestration of pollutants is estimated based on the Leaf Area Index (LAI) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) derived dataset estimates of LAI and the percentage land cover obtained from the National Land Cover Database (NLCD) for the year 2010. Calculation of pollution removal capacity using local environmental data indicates that grasslands and shrublands remove a total of 6.42 million tonnes of air pollutants in the United States and the associated monetary benefits total 268 million. Human health impacts and associated monetary value due to pollution removal was observed to be significantly high in urban areas indicating that grasslands and shrublands are equally critical as canopy in improving air quality and human health in urban regions.

  1. Factors affecting the ozone sensitivity of temperate European grasslands: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Bassin, S. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland)]. E-mail: seraina.bassin@fal.admin.ch; Volk, M. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland)

    2007-04-15

    This overview of experimentally induced effects of ozone aims to identify physiological and ecological principles, which can be used to classify the sensitivity to ozone of temperate grassland communities in Europe. The analysis of data from experiments with single plants, binary mixtures and multi-species communities illustrates the difficulties to relate individual responses to communities, and thus to identify grassland communities most at risk. Although there is increasing evidence that communities can be separated into broad classes of ozone sensitivity, the database from experiments under realistic conditions with representative systems is too small to draw firm conclusions. But it appears that risk assessments, based on results from individuals or immature mixtures exposed in chambers, are only applicable to intensively managed, productive grasslands, and that the risk of ozone damage for most of perennial grasslands with lower productivity tends to be less than previously expected. - An overview of experimentally induced ozone effects suggests that temperate grasslands could be separated into broad classes of ozone sensitivity based on physiological and ecological principles.

  2. Floristic composition, environmental variation and species distribution patterns in burned grassland in southern Brazil.

    Science.gov (United States)

    Overbeck, G E; Müller, S C; Pillar, V D; Pfadenhauer, J

    2006-11-01

    In regularly burned grassland on Morro Santana, Porto Alegre, RS, Brazil, we investigated differences in the floristic composition and their relation to soil properties, aspect and distance from the forest border. In 48 plots of 0.75 m2, we identified a total of 201 species from a local species pool of approximately 450 to 500 species. Most species occurred in low frequencies, showing clumpy distribution patterns in the studied area. Multivariate analysis showed that plots close to the forest edge clearly differed from plots in the open grassland concerning composition and structure. Plots exposed to the north differed from plots on the top of the hill both in the composition of species as well as in soil variables, mainly due to shallower soil in the former. No strong relation between soil properties and variation in vegetation composition could be detected at a finer scale. The studied grassland, as all grassland vegetation in southern Brazil, is very rich in species compared to other grassland formations worldwide. However, this high biodiversity and conservational value of Campos vegetation in general has so far not been recognized properly. Disturbance is essential to maintain this open vegetation type and its species richness. Fire should be considered as a management option in the absence of grazing.

  3. Habitat fragmentation effects on birds in grasslands and wetlands: A critique of our knowledge

    Science.gov (United States)

    Johnson, D.H.

    2001-01-01

    Habitat fragmentation exacerbates the problem of habitat loss for grassland and wetland birds. Remaining patches of grasslands and wetlands may be too small, too isolated, and too influenced by edge effects to maintain viable populations of some breeding birds. Knowledge of the effects of fragmentation on bird populations is critically important for decisions about reserve design, grassland and wetland management, and implementation of cropland set-aside programs that benefit wildlife. In my review of research that has been conducted on habitat fragmentation, I found at least five common problems in the methodology used. The results of many studies are compromised by these problems: passive sampling (sampling larger areas in larger patches), confounding effects of habitat heterogeneity, consequences of inappropriate pooling of data from different species, artifacts associated with artificial nest data, and definition of actual habitat patches. As expected, some large-bodied birds with large territorial requirements, such as the northern harrier (Circus cyaneus), appear area sensitive. In addition, some small species of grassland birds favor patches of habitat far in excess of their territory size, including the Savannah (Passerculus sandwichensis), grasshopper (Ammodramus savannarum) and Henslow's (A. henslowii) sparrows, and the bobolink (Dolichonyx oryzivorus). Other species may be area sensitive as well, but the data are ambiguous. Area sensitivity among wetland birds remains unknown since virtually no studies have been based on solid methodologies. We need further research on grassland bird response to habitat that distinguishes supportable conclusions from those that may be artifactual.

  4. Factors affecting the ozone sensitivity of temperate European grasslands: An overview

    International Nuclear Information System (INIS)

    Bassin, S.; Volk, M.; Fuhrer, J.

    2007-01-01

    This overview of experimentally induced effects of ozone aims to identify physiological and ecological principles, which can be used to classify the sensitivity to ozone of temperate grassland communities in Europe. The analysis of data from experiments with single plants, binary mixtures and multi-species communities illustrates the difficulties to relate individual responses to communities, and thus to identify grassland communities most at risk. Although there is increasing evidence that communities can be separated into broad classes of ozone sensitivity, the database from experiments under realistic conditions with representative systems is too small to draw firm conclusions. But it appears that risk assessments, based on results from individuals or immature mixtures exposed in chambers, are only applicable to intensively managed, productive grasslands, and that the risk of ozone damage for most of perennial grasslands with lower productivity tends to be less than previously expected. - An overview of experimentally induced ozone effects suggests that temperate grasslands could be separated into broad classes of ozone sensitivity based on physiological and ecological principles

  5. DIVERSITY OF PLANT COMMUNITIES IN SECONDARY SUCCESSION OF IMPERATA GRASSLANDS IN SAMBOJA LESTARI, EAST KALIMANTAN, INDONESIA

    Directory of Open Access Journals (Sweden)

    Ishak Yassir

    2016-06-01

    Full Text Available Regeneration of  Imperata grassland areas is becoming increasingly important, both to create new secondary forest and to recover the original biodiversity. The diversity of  plant communities in secondary succession of  Imperata grasslands was studied using 45 subplots of  9 linear transects (10 m x 100 m. Data was collected and all stems over 10 cm dbh were identified, the Importance Values Index (IVI for all trees were calculated, saplings and seedlings were counted  and analysed, and soil samples were taken and analysed. Results showed that  after more than 10 years of  regeneration, 65 families were encountered consisting of  164 species, which were dominated by Vernonia arborea Buch.-Ham, Vitex pinnata L., Macaranga gigantea (Reichb.f. & Zoll. Muell.Arg., Symplocos crassipes C.B. Clarke, Artocarpus odoratissimus Miq., and Bridelia glauca Blume. The effects of  regeneration, from Imperata grassland to secondary forest, on soil were the strongest in the A-horizon where an increase in carbon, N content, and pH were observed. Our result shows that Imperata grasslands appear to be permanent because of  frequent fires and human interferences and so far few efforts have been made to promote sustainable rehabilitation. If  protected from fire and other disturbances, such as shifting cultivation, Imperata grassland will grow and develop into secondary forest.

  6. Association of wintering raptors with Conservation Reserve Enhancement Program grasslands in Pennsylvania

    Science.gov (United States)

    Wilson, A.; Brittingham, M.; Grove, G.

    2010-01-01

    Conservation grasslands can provide valuable habitat resource for breeding songbirds, but their value for wintering raptors has received little attention. We hypothesized that increased availability of grassland habitat through the Conservation Reserve Enhancement Program (CREP) has resulted in an increase or redistribution in numbers of four species of raptors in Pennsylvania since 2001. We tested this by analyzing winter raptor counts from volunteer surveys, conducted from 2001 to 2008, for Red-tailed Hawks (Buteo jamaicensis), Rough-legged Hawks (Buteo lagopus), Northern Harriers (Circus cyaneus), and American Kestrels (Falco sparverius). During that period, numbers of wintering Northern Harriers increased by more than 20% per year. Log-linear Poisson regression models show that all four species increased in the region of Pennsylvania that had the most and longest-established conservation grasslands. At the county scale (N= 67), Bayesian spatial models showed that spatial and temporal population trends of all four species were positively correlated with the amount of conservation grassland. This relationship was particularly strong for Northern Harriers, with numbers predicted to increase by 35.7% per year for each additional 1% of farmland enrolled in CREP. Our results suggest that conservation grasslands are likely the primary cause of the increase in numbers of wintering Northern Harriers in Pennsylvania since 2001. ?? 2010 The Authors. Journal of Field Ornithology ?? 2010 Association of Field Ornithologists.

  7. Assessment of Grassland Health Based on Spatial Information Technology in Changji Autonomous Prefecture, Xinjiang

    Science.gov (United States)

    Du, M. J.; Zheng, J. H.; Mu, C.

    2018-04-01

    Based on the "pressure-state-response" (PSR) model, comprehensively applied GIS and RS techniques, 20 evaluation indicators were selected based on pressure, state and response, the entropy weight method was used to determine the weight of each index and build a grassland health evaluation system in Changji Prefecture, Xinjiang. Based on this, evaluation and dynamic analysis of grassland health in Changji Prefecture from 2000 to 2016, using GIS/RS technology, the trend of grassland health status in Changji is analyzed and studied. The results show that: 1) Grassland with low health leveld, lower health level, sub-health level, health level and high health level accounts for 1.46 %,27.67 %,38.35 %,29.21 % and 3.31 % of the total area of Changji. Qitai County, Hutubi County, and Manas County are lower health levels, Jimsar County, Changji City, and Mulei County are at a relatively high level, and Fukang City has a healthy level of health. 2) The level of grassland health in Changji County decreased slightly during the 17 years, accounting for 38.42 % of the total area. The area of 23,87 % showed a stable trend, and the improved area accounted for 37.31 % of the vertical surface area.

  8. In silico peptide-binding predictions of passerine MHC class I reveal similarities across distantly related species, suggesting convergence on the level of protein function.

    Science.gov (United States)

    Follin, Elna; Karlsson, Maria; Lundegaard, Claus; Nielsen, Morten; Wallin, Stefan; Paulsson, Kajsa; Westerdahl, Helena

    2013-04-01

    The major histocompatibility complex (MHC) genes are the most polymorphic genes found in the vertebrate genome, and they encode proteins that play an essential role in the adaptive immune response. Many songbirds (passerines) have been shown to have a large number of transcribed MHC class I genes compared to most mammals. To elucidate the reason for this large number of genes, we compared 14 MHC class I alleles (α1-α3 domains), from great reed warbler, house sparrow and tree sparrow, via phylogenetic analysis, homology modelling and in silico peptide-binding predictions to investigate their functional and genetic relationships. We found more pronounced clustering of the MHC class I allomorphs (allele specific proteins) in regards to their function (peptide-binding specificities) compared to their genetic relationships (amino acid sequences), indicating that the high number of alleles is of functional significance. The MHC class I allomorphs from house sparrow and tree sparrow, species that diverged 10 million years ago (MYA), had overlapping peptide-binding specificities, and these similarities across species were also confirmed in phylogenetic analyses based on amino acid sequences. Notably, there were also overlapping peptide-binding specificities in the allomorphs from house sparrow and great reed warbler, although these species diverged 30 MYA. This overlap was not found in a tree based on amino acid sequences. Our interpretation is that convergent evolution on the level of the protein function, possibly driven by selection from shared pathogens, has resulted in allomorphs with similar peptide-binding repertoires, although trans-species evolution in combination with gene conversion cannot be ruled out.

  9. Advanced long-term bird banding and climate data mining in spring confirm passerine population declines for the Northeast Chinese-Russian flyway

    Science.gov (United States)

    Jiao, Shengwu; Huettmann, Falk; Guo, Yumin; Li, Xianda; Ouyang, Yanlan

    2016-09-01

    The migration of birds is fascinating for humans but it's also a serious environmental monitoring and management issue on a global level. Bird banding using mistnets has been the method of choice for decades worldwide; linking these data with climate data allows to infer on global warming and outlier events. However, good methods to achieve this effectively in time and space for many species are still missing; data for Asia are specifically sparse and often 'messy'. Here we present a data mining summary information for data from two bird banding stations (Gaofeng and Qingfeng) along the vast Northeast Chinese-Russian flyway. Bird data were collected during spring 2002-2011 with standardized techniques and then linked with related climate data in the banding as well as the wintering sites. This creates a complex data set which is based on a decade and which includes many predictors. This first-time data mining analysis with 'data cloning' and machine learning methods (boosted regression trees) shows how to extract the major signals in this unique dataset from highly correlated and interacting predictors. Our results indicate a large-scale warming trend for the flyway, with a start in 2003, and a freezing rain outlier event in 2008; the last years remained on a rather warm level. All evidence along this vast flyway supports major changes, warming trends, habitat losses and consequently strong passerine declines. Presumably human pressures are a major factor either way and we propose to address these problems immediately for betterment if meaningful conservation targets are to be met.

  10. Population connectivity and the effectiveness of marine protected areas to protect vulnerable, exploited and endemic coral reef fishes at an endemic hotspot

    KAUST Repository

    Van Der Meer, Martin H.; Berumen, Michael L.; Hobbs, Jean Paul Adrian; Van Herwerden, Lynne Van

    2014-01-01

    -replenishment, and the absence of MPAs at NI needs to be rectified to ensure the persistence of endemic species at this location. Other endemic fishes exhibit similar patterns of high self-replenishment across the four locations, indicating that a single spatial management

  11. Changes of agrochemical properties of cambisol under grassland after abandonment

    Directory of Open Access Journals (Sweden)

    Ján Jančovič

    2012-01-01

    Full Text Available On the grassland (association Lolio-Cynosuretum cristati R. 1937 with brown acidic soil (cambisol the basic agrochemical properties (pH, Cox, Nt, P, K was studied during the years 1986–2006. Various systems of management (fertilizing + cutting, liming, no management had different influences to the cambisol qualities, but had not so significant effect. The pH of the soil decreased after application of mineral fertilization and also in the period without anthropogenic interference. The balanced content of oxidizable carbon (Cox preserved during the experimental period. The total nitrogen content (Nt increased in the period of fertilization and the aftermath of fertilization. The content of phosphorus (P decreased significantly in the years of fertilization and this trend continued after the absence of fertilization too. The content of potassium (K decreased in the period of fertilization, except for a variant with PK nutrition. The content of potassium (K increased on the all variants in both sampling depths of almost 1.5-fold after a period without management. We found a significant effect of year and depth of soil sampling for most of soil parameters. Variants had not significant impact on all evaluated soil characteristics. Between the years there was relatively great variability at the available nutrients values (8–75 %. The available phosphorus had greatest variability (19–96 % and also potassium (18–82 %. Medium till small variability was characteristic for pH (9–14 %, Cox (17–19 % and Nt (8–16 %. The results are indicating that changes of management systems mean not automatically changes of soil features.

  12. Effects of wind-energy facilities on grassland bird distributions

    Science.gov (United States)

    Shaffer, Jill A.; Buhl, Deb

    2016-01-01

    The contribution of renewable energy to meet worldwide demand continues to grow. Wind energy is one of the fastest growing renewable sectors, but new wind facilities are often placed in prime wildlife habitat. Long-term studies that incorporate a rigorous statistical design to evaluate the effects of wind facilities on wildlife are rare. We conducted a before-after-control-impact (BACI) assessment to determine if wind facilities placed in native mixed-grass prairies displaced breeding grassland birds. During 2003–2012, we monitored changes in bird density in 3 study areas in North Dakota and South Dakota (U.S.A.). We examined whether displacement or attraction occurred 1 year after construction (immediate effect) and the average displacement or attraction 2–5 years after construction (delayed effect). We tested for these effects overall and within distance bands of 100, 200, 300, and >300 m from turbines. We observed displacement for 7 of 9 species. One species was unaffected by wind facilities and one species exhibited attraction. Displacement and attraction generally occurred within 100 m and often extended up to 300 m. In a few instances, displacement extended beyond 300 m. Displacement and attraction occurred 1 year after construction and persisted at least 5 years. Our research provides a framework for applying a BACI design to displacement studies and highlights the erroneous conclusions that can be made without the benefit of adopting such a design. More broadly, species-specific behaviors can be used to inform management decisions about turbine placement and the potential impact to individual species. Additionally, the avoidance distance metrics we estimated can facilitate future development of models evaluating impacts of wind facilities under differing land-use scenarios.

  13. Precipitation alters interactions in a grassland ecological community.

    Science.gov (United States)

    Deguines, Nicolas; Brashares, Justin S; Prugh, Laura R

    2017-03-01

    Climate change is transforming precipitation regimes world-wide. Changes in precipitation regimes are known to have powerful effects on plant productivity, but the consequences of these shifts for the dynamics of ecological communities are poorly understood. This knowledge gap hinders our ability to anticipate and mitigate the impacts of climate change on biodiversity. Precipitation may affect fauna through direct effects on physiology, behaviour or demography, through plant-mediated indirect effects, or by modifying interactions among species. In this paper, we examined the response of a semi-arid ecological community to a fivefold change in precipitation over 7 years. We examined the effects of precipitation on the dynamics of a grassland ecosystem in central California from 2007 to 2013. We conducted vegetation surveys, pitfall trapping of invertebrates, visual surveys of lizards and capture-mark-recapture surveys of rodents on 30 plots each year. We used structural equation modelling to evaluate the direct, indirect and modifying effects of precipitation on plants, ants, beetles, orthopterans, kangaroo rats, ground squirrels and lizards. We found pervasive effects of precipitation on the ecological community. Although precipitation increased plant biomass, direct effects on fauna were often stronger than plant-mediated effects. In addition, precipitation altered the sign or strength of consumer-resource and facilitative interactions among the faunal community such that negative or neutral interactions became positive or vice versa with increasing precipitation. These findings indicate that precipitation influences ecological communities in multiple ways beyond its recognized effects on primary productivity. Stochastic variation in precipitation may weaken the average strength of biotic interactions over time, thereby increasing ecosystem stability and resilience to climate change. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological

  14. Burkholderia megalochromosomata sp. nov., isolated from grassland soil.

    Science.gov (United States)

    Baek, Inwoo; Seo, Boram; Lee, Imchang; Lee, Kihyun; Park, Sang-Cheol; Yi, Hana; Chun, Jongsik

    2015-03-01

    A Gram-stain negative, rod-shaped, non-spore-forming, obligate aerobic bacterial strain, JC2949(T), was isolated from grassland soil in Gwanak Mountain, Seoul, Republic of Korea. Phylogenetic analysis, based on 16S rRNA sequences, indicated that strain JC2949(T) belongs to the genus Burkholderia, showing highest sequence similarities with Burkholderia grimmiae R27(T) (98.8 %), Burkholderia cordobensis LMG 27620(T) (98.6 %), Burkholderia jiangsuensis MP-1T(T) (98.6 %), Burkholderia zhejiangensis OP-1(T) (98.5 %), Burkholderia humi LMG 22934(T) (97.5 %), Burkholderia terrestris LMG 22937(T) (97.3 %), Burkholderia telluris LMG 22936(T) (97.2 %) and Burkholderia glathei ATCC 29195(T) (97.0 %). The major fatty acids of strain JC2949(T) were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. Its predominant polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown amino phospholipid. The dominant isoprenoid quinone was ubiquinone Q-8. The pairwise average nucleotide identity values between strain JC2949(T) and the genomes of 30 other species of the genus Burkholderia ranged from 73.4-90.4 %, indicating that the isolate is a novel genomic species within this genus. Based on phenotypic and chemotaxonomic comparisons, it is clear that strain JC2949(T) represents a novel species of the genus Burkholderia. We propose the name for this novel species to be Burkholderia megalochromosomata sp. nov. The type strain is JC2949(T) ( = KACC 17925(T) = JCM 19905(T)). © 2015 IUMS.

  15. Restoration of species-rich grasslands on ex-arable land: Seed addition outweighs soil fertility reduction

    NARCIS (Netherlands)

    Kardol, P.; Van der Wal, A.; Bezemer, T.M.; De Boer, W.; Duyts, H.; Holtkamp, R.; Van der Putten, W.H.

    2008-01-01

    A common practice in biodiversity conservation is restoration of former species-rich grassland on ex-arable land. Major constraints for grassland restoration are high soil fertility and limited dispersal ability of plant species to target sites. Usually, studies focus on soil fertility or on methods

  16. Effect of climate change on halophytic grasslands loss and its impact in the viability of Gopherus flavomarginatus

    Directory of Open Access Journals (Sweden)

    Jorge Luis Becerra-López

    2017-08-01

    Full Text Available The decrease of the habitat is one of the main factors that affect the survival of G. flavomarginatus. This study assesses the halophytic grasslands loss over a period of 30 years in the distribution area of the Bolson tortoise and the effects of climate change on the habitat suitability of these grasslands and its possible impact on this tortoise. Grassland loss was assessed by an analysis of symmetric differences and the habitat suitability model was carried out by the method of overlapping layers raster. Our results showed a grassland loss of 63.7%; however, our current habitat suitability model points out that much of the grassland loss has occurred where the environmental conditions are suitable. These results suggest that anthropic activity is a main factor in the habitat disturbance in the study area. Likewise, the models for years 2050 and 2070 under the criteria RCP 2.6, RCP 4.5, RCP 6.0, suggest that anthropic activity will continue be the main cause of the grassland loss. Therefore, considering the association between the Bolson tortoise and grassland halophyte Hilaria mutica, which comprises around 60% of its diet, the viability of the Bolson tortoise depends largely on strategies aimed at protecting the soil that allow the presence of this grassland.

  17. The false promises of coal exploitation: How mining affects herdsmen well-being in the grassland ecosystems of Inner Mongolia

    International Nuclear Information System (INIS)

    Dai, G.S.; Ulgiati, S.; Zhang, Y.S.; Yu, B.H.; Kang, M.Y.; Jin, Y.; Dong, X.B.; Zhang, X.S.

    2014-01-01

    The grasslands of Inner Mongolia are not only the source of the necessary resources for the survival and development of herdsmen, but also represent a significant green ecological barrier in North China. Coal-mining production is important in maintaining GDP growth in Inner Mongolia. However, over-exploitation has created serious problems, such as pollution of the environment and significant decreases in grassland ecosystem services, in addition to impacting the well-being of herdsmen and other humans. Based on questionnaires survey performed among 864 herdsmen addressing the relationship between coal exploitation in grasslands and human well-being in Xilinguole League in Inner Mongolia, we found that (1) coal resource exploitation in these grasslands does not benefit the herdsmen by increasing their income; (2) the rapid development of this resource has not obviously materially improved the life of the herdsmen; and (3) these activities have increased the risks that herdsman will have to endure in the future. Overall, coal resource exploitation in grasslands has more negative than positive effects on the well-being of herdsmen. We propose the conservation of coal resources and improvement of ecological compensation should be carried out without blindly pursuing economic growth, instead of focusing on economic development and structural adjustments. - Highlights: • Evaluation of the human well-being of the Xilinguole grassland, Inner Mongolia, China. • Impact of mining affects herdsmen well-being in grassland ecosystem. • Quantity of questionnaires survey. • Addressing the relationship between coal exploitation in grasslands and human well-being

  18. Does resource availability, resource heterogeneity or species turnover mediate changes in plant species richness in grazed grasslands?

    NARCIS (Netherlands)

    Bakker, C; Blair, JM; Knapp, AK

    2003-01-01

    Grazing by large ungulates often increases plant species richness in grasslands of moderate to high productivity. In a mesic North American grassland with and without the presence of bison (Bos bison), a native ungulate grazer, three non-exclusive hypotheses for increased plant species richness in

  19. Evaluating effects of habitat loss and land-use continuity on ant species richness in seminatural grassland remnants.

    Science.gov (United States)

    Dauber, Jens; Bengtsson, Jan; Lenoir, Lisette

    2006-08-01

    Seminatural grasslands in Europe are susceptible to habitat destruction and fragmentation that result in negative effects on biodiversity because of increased isolation and area effects on extinction rate. However even small habitatpatches of seminatural grasslands might be of value for conservation and restoration of species richness in a landscape with a long history of management, which has been argued to lead to high species richness. We tested whether ant communities have been negatively affected by habitat loss and increased isolation of seminatural grasslands during the twentieth century. We examined species richness and community composition in seminatural grasslands of different size in a mosaic landscape in Central Sweden. Grasslands managed continuously over centuries harbored species-rich and ecologically diverse ant communities. Grassland remnant size had no effect on ant species richness. Small grassland remnants did not harbor a nested subset of the ant species of larger habitats. Community composition of ants was mainly affected by habitat conditions. Our results suggest that the abandonment of traditional land use and the encroachment of trees, rather than the effects of fragmentation, are important for species composition in seminatural grasslands. Our results highlight the importance of considering land-use continuity and dispersal ability of thefocal organisms when examining the effects of habitat loss and fragmentation on biodiversity. Landscape history should be considered in conservation programs focusing on effects of land-use change.

  20. Changes in vegetation types and Ellenberg indicator values after 65 years of fertilizer application in the Rengen Grassland Experiment, Germany

    NARCIS (Netherlands)

    Chytry, M.; Hejcman, M.; Hennekens, S.M.; Schellberg, J.

    2009-01-01

    Question: How does semi-natural grassland diversify after 65 years of differential application of Ca, N, P, and K fertilizers? Is fertilizer application adequately reflected by the Ellenberg indicator values (EIVs)? Location: Eifel Mountains, West Germany. Methods: The Rengen Grassland Experiment

  1. Effects of erosion from mounds of different termite genera on distinct functional grassland types in an African savannah

    NARCIS (Netherlands)

    Gosling, Cleo M.; Cromsigt, Joris P. G. M.; Mpanza, Nokukhanya; Olff, Han

    A key aspect of savannah vegetation heterogeneity is mosaics formed by two functional grassland types, bunch grasslands, and grazing lawns. We investigated the role of termites, important ecosystem engineers, in creating high-nutrient patches in the form of grazing lawns. Some of the ways termites

  2. Mapping grassland productivity with 250-m eMODIS NDVI and SSURGO database over the Greater Platte River Basin, USA

    Science.gov (United States)

    Gu, Yingxin; Wylie, Bruce K.; Bliss, Norman B.

    2013-01-01

    This study assessed and described a relationship between satellite-derived growing season averaged Normalized Difference Vegetation Index (NDVI) and annual productivity for grasslands within the Greater Platte River Basin (GPRB) of the United States. We compared growing season averaged NDVI (GSN) with Soil Survey Geographic (SSURGO) database rangeland productivity and flux tower Gross Primary Productivity (GPP) for grassland areas. The GSN was calculated for each of nine years (2000–2008) using the 7-day composite 250-m eMODIS (expedited Moderate Resolution Imaging Spectroradiometer) NDVI data. Strong correlations exist between the nine-year mean GSN (MGSN) and SSURGO annual productivity for grasslands (R2 = 0.74 for approximately 8000 pixels randomly selected from eight homogeneous regions within the GPRB; R2 = 0.96 for the 14 cluster-averaged points). Results also reveal a strong correlation between GSN and flux tower growing season averaged GPP (R2 = 0.71). Finally, we developed an empirical equation to estimate grassland productivity based on the MGSN. Spatially explicit estimates of grassland productivity over the GPRB were generated, which improved the regional consistency of SSURGO grassland productivity data and can help scientists and land managers to better understand the actual biophysical and ecological characteristics of grassland systems in the GPRB. This final estimated grassland production map can also be used as an input for biogeochemical, ecological, and climate change models.

  3. Total soil C and N sequestration in a grassland following 10 years of free air CO2 enrichment

    NARCIS (Netherlands)

    Kessel, van C.; Boots, B.; Graaff, de M.A.; Harris, D.; Blum, H.; Six, J.

    2006-01-01

    Soil C sequestration may mitigate rising levels of atmospheric CO2. However, it has yet to be determined whether net soil C sequestration occurs in N-rich grasslands exposed to long-term elevated CO2. This study examined whether N-fertilized grasslands exposed to elevated CO2 sequestered additional

  4. Base cation depletion, eutrophication and acidification of species-rich grasslands in response to long-term simulated nitrogen deposition

    Energy Technology Data Exchange (ETDEWEB)

    Horswill, Paul [Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN (United Kingdom)], E-mail: paul.horswill@naturalengland.org.uk; O' Sullivan, Odhran; Phoenix, Gareth K.; Lee, John A.; Leake, Jonathan R. [Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN (United Kingdom)

    2008-09-15

    Pollutant nitrogen deposition effects on soil and foliar element concentrations were investigated in acidic and limestone grasslands, located in one of the most nitrogen and acid rain polluted regions of the UK, using plots treated for 8-10 years with 35-140 kg N ha{sup -2} y{sup -1} as NH{sub 4}NO{sub 3}. Historic data suggests both grasslands have acidified over the past 50 years. Nitrogen deposition treatments caused the grassland soils to lose 23-35% of their total available bases (Ca, Mg, K, and Na) and they became acidified by 0.2-0.4 pH units. Aluminium, iron and manganese were mobilised and taken up by limestone grassland forbs and were translocated down the acid grassland soil. Mineral nitrogen availability increased in both grasslands and many species showed foliar N enrichment. This study provides the first definitive evidence that nitrogen deposition depletes base cations from grassland soils. The resulting acidification, metal mobilisation and eutrophication are implicated in driving floristic changes. - Nitrogen deposition causes base cation depletion, acidification and eutrophication of semi-natural grassland soils.

  5. Using the theory of planned behavior to identify key beliefs underlying Brazilian cattle farmers' intention to use improved natural grassland

    NARCIS (Netherlands)

    Rossi Borges, Joao; Tauer, Loren Willian; Oude Lansink, Alfons

    2016-01-01

    In biome Pampa, Brazil, cattle farmers have managed the natural grasslands using practices that result in overgrazing, low productivity and low farm income. In addition, farmers in the region converted natural grasslands from beef production to more profitable activities, such as cash crops. This

  6. Application of satellite remote sensing for mapping wind erosion risk and dusk emission-deposition in Inner Mongolia grassland, China

    NARCIS (Netherlands)

    Reiche, M.; Funk, R.; Zhang, Z.; Hoffmann, C.; Reiche, J.; Wehrhan, M.; Li, Y.; Sommer, M.

    2012-01-01

    Intensive grazing leads to land degradation and desertification of grassland ecosystems followed by serious environmental and social problems. The Xilingol steppe grassland in Inner Mongolia, China, which has been a sink area for dust for centuries, is strongly affected by the negative effects of

  7. Fate of semi-natural grassland in England between 1960 and 2013: A test of national conservation policy

    Directory of Open Access Journals (Sweden)

    Lucy E. Ridding

    2015-07-01

    Full Text Available It is well documented that significant losses in semi-natural grassland occurred across Europe during the second half of the twentieth century. However, comparatively few studies have investigated and quantified the fate of large numbers of individual grassland areas. This is important for understanding the causes of decline, and consequently establishing new policies to conserve and restore lost habitats. This study addresses this problem; GIS was used to compare historic survey data collected between 1960 and 1981 with two contemporary spatial datasets of habitats in England. The datasets included the Priority Habitats Inventory 2013 and the Land Cover Map 2007 and this was undertaken for different types of semi-natural grassland across England. Considerable decreases occurred across the different grassland types, with a loss of 47% of studied semi-natural grasslands sites in England over 32–53 years. Of this, the majority of grassland was lost to conversion to agriculturally-improved grassland or arable cultivation, 45% and 43% respectively. Changes to woodland and urban areas were also evident, but on a much smaller scale. Sites receiving statutory protection as a Site of Special Scientific Interest were found to have retained more grassland (91%, compared with non-protected sites (27%, thus highlighting the effectiveness of this aspect of current conservation policy in England, and the need for this to continue in the future.

  8. Faunal isotope records reveal trophic and nutrient dynamics in twentieth century Yellowstone grasslands.

    Science.gov (United States)

    Fox-Dobbs, Kena; Nelson, Abigail A; Koch, Paul L; Leonard, Jennifer A

    2012-10-23

    Population sizes and movement patterns of ungulate grazers and their predators have fluctuated dramatically over the past few centuries, largely owing to overharvesting, land-use change and historic management. We used δ(13)C and δ(15)N values measured from bone collagen of historic and recent gray wolves and their potential primary prey from Yellowstone National Park to gain insight into the trophic dynamics and nutrient conditions of historic and modern grasslands. The diet of reintroduced wolves closely parallels that of the historic population. We suggest that a significant shift in faunal δ(15)N values over the past century reflects impacts of anthropogenic environmental changes on grassland ecosystems, including grazer-mediated shifts in grassland nitrogen cycle processes.

  9. 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.

  10. Conservation Reserve Program mitigates grassland loss in the lesser prairie-chicken range of Kansas

    Science.gov (United States)

    Haukos, David A.; Spencer, David; Hagen, Christian A.; Daniels, Melinda D.; Goodin, Doug

    2017-01-01

    Since the beginning of the 20th century, the overall occupied range of the lesser prairie-chicken (Tympanuchus pallidicinctus) has declined by 84% commensurate with population trends. Much of this decline has been attributed to the loss and fragmentation of native grasslands throughout the lesser prairie-chicken range. However, quantification of changes in land cover in the distribution of the lesser prairie-chicken is lacking. Our objectives were to (1) document changes in the areal extent and connectivity of grasslands in the identified lesser prairie-chicken range in Kansas, USA, (>60% of extant lesser prairie-chicken population) from the 1950s to 2013 using remotely sensed data and (2) assess the potential of the Conservation Reserve Program (U.S. Department of Agriculture Program converting cropland to permanent cover; CRP) to mitigate grassland loss. Digital land cover maps were generated on a decadal time step through spectral classification of LANDSAT images and visual analysis of aerial photographs (1950s and 1960s). Landscape composition and configuration were assessed using FRAGSTATS to compute a variety of landscape metrics measuring changes in the amount of grassland present as well as changes in the size and configuration of grassland patches. With the exception of a single regional portion of the range, nearly all of the grassland converted to cropland in the lesser prairie-chicken range of Kansas occurred prior to the 1950s. Prior to the implementation of CRP, the amount of grassland decreased 3.6% between the 1950s and 1985 from 18,455 km2 to 17,788 km2. Since 1985, the overall amount of grassland in the lesser prairie-chicken range has increased 11.9% to 19,898 km2 due to implementation of CRP, although the area of grassland decreased between 1994 and 2013 as CRP contracts were not renewed by landowners. Since 1986 grassland in Kansas became more connected and less fragmented in response to the CRP. While the CRP has been successful in

  11. Conservation Reserve Program mitigates grassland loss in the lesser prairie-chicken range of Kansas

    Directory of Open Access Journals (Sweden)

    David Spencer

    2017-01-01

    Full Text Available Since the beginning of the 20th century, the overall occupied range of the lesser prairie-chicken (Tympanuchus pallidicinctus has declined by 84% commensurate with population trends. Much of this decline has been attributed to the loss and fragmentation of native grasslands throughout the lesser prairie-chicken range. However, quantification of changes in land cover in the distribution of the lesser prairie-chicken is lacking. Our objectives were to (1 document changes in the areal extent and connectivity of grasslands in the identified lesser prairie-chicken range in Kansas, USA, (>60% of extant lesser prairie-chicken population from the 1950s to 2013 using remotely sensed data and (2 assess the potential of the Conservation Reserve Program (U.S. Department of Agriculture Program converting cropland to permanent cover; CRP to mitigate grassland loss. Digital land cover maps were generated on a decadal time step through spectral classification of LANDSAT images and visual analysis of aerial photographs (1950s and 1960s. Landscape composition and configuration were assessed using FRAGSTATS to compute a variety of landscape metrics measuring changes in the amount of grassland present as well as changes in the size and configuration of grassland patches. With the exception of a single regional portion of the range, nearly all of the grassland converted to cropland in the lesser prairie-chicken range of Kansas occurred prior to the 1950s. Prior to the implementation of CRP, the amount of grassland decreased 3.6% between the 1950s and 1985 from 18,455 km2 to 17,788 km2. Since 1985, the overall amount of grassland in the lesser prairie-chicken range has increased 11.9% to 19,898 km2 due to implementation of CRP, although the area of grassland decreased between 1994 and 2013 as CRP contracts were not renewed by landowners. Since 1986 grassland in Kansas became more connected and less fragmented in response to the CRP. While the CRP has been successful

  12. The impact of black wattle encroachment of indigenous grasslands on soil carbon, Eastern Cape, South Africa

    DEFF Research Database (Denmark)

    Oelofse, Myles; Birch-Thomsen, Torben; Magid, Jakob

    2016-01-01

    adverse environmental impacts in South Africa. Little is known about the effects of black wattle encroachment on soil carbon, therefore the aim of this study was to investigate the impact of black wattle encroachment of natural grassland on soil carbon stocks and dynamics. Focussing on two sites...... in the Eastern Cape, South Africa, the study analysed carbon stocks in soil and litter on a chronosequence of black wattle stands of varying ages (up to >50 years) and compared these with adjacent native grassland. The study found that woody encroachment of grassland at one site had an insignificant effect...... on soil and litter carbon stocks. The second site showed a clear decline in combined soil and litter carbon stocks following wattle encroachment. The lowest stock was in the oldest wattle stand, meaning that carbon stocks are still declining after 50 years of encroachment. The results from the two sites...

  13. Diversity distribution patterns of Chinese endemic seed plant species and their implications for conservation planning

    Science.gov (United States)

    Huang, Jihong; Huang, Jianhua; Lu, Xinghui; Ma, Keping

    2016-01-01

    Endemism is an important concept in biogeography and biodiversity conservation. China is one of the richest countries in biodiversity, with very high levels of plant endemism. In this study, we analysed the distribution patterns of diversity, the degree of differentiation, and the endemicity of Chinese endemic seed plants using the floristic unit as a basic spatial analysis unit and 11 indices. The analysis was based on distribution data of 24,951 native seed plant species (excluding subspecies and varieties) and 12,980 Chinese endemic seed plant species, which were sourced from both specimen records and published references. The distribution patterns of Chinese endemic flora were generally consistent but disproportionate across China for diversity, degree of differentiation and endemicity. The South Hengduan Mountains Subregion had the highest values for all indices. At the regional level, both the Hengduan Mountains and the Central China regions were highest in diversity and degrees of differentiation. However, both the rate of local endemic to native species and the rate of local to Chinese endemic species were highest in the Taiwan Region and the South Taiwan Region. The Hengduan Mountains Region and the Central China Region are two key conservation priority areas for Chinese endemic seed plants. PMID:27658845

  14. ANALYSIS OF ENDEMISM OF THE XEROPHILOUS FLORA IN THE RUSSIAN CAUCASUS

    Directory of Open Access Journals (Sweden)

    M. A. Taysumov

    2017-01-01

    Full Text Available The aim of our research is to study the endemics of the xerophilous flora of the Russian Caucasus in connection with the matter of knowing the genesis.Methods. The study is based on the field research expeditions.Findings. The presence of endemic species in flora is an indicator of its originality, and the degree of originality is determined by the extent of the endemic species. In general, according to our geographic analysis, the number of endemic species in xerophilous flora of the Russian Caucasus accounts for 32% (326 species, of which 25% of all endemic species have natural habitats within entire Caucasus, 66% are widespread in the Greater Caucasus, and 9% in the Pre-Caucasian region.Conclusion. Endemic species of xerophytes of the flora, in their overwhelming majority, are euxerophytes, and most steno-endemics also belong to this group of xerophytes. In a systematic aspect, the leading family, containing the largest number of endemic species, is Asteraceae (in percentage terms - Lamiaceae and Jurinea is a leading genus (in percentage terms - Psephellus. In relation to the substrate, calcixerophytes are the dominants and most saturated endemics in quantitative terms are the belt of mountain xerophytes. The predominant biomes are hemicryptophytes; as compared with the number of biomorphes, among chamaephytes there is the biggest quantity of endemics

  15. Evidence for endemic chikungunya virus infections in Bandung, Indonesia.

    Directory of Open Access Journals (Sweden)

    Herman Kosasih

    Full Text Available Chikungunya virus (CHIKV is known to cause sporadic or explosive outbreaks. However, little is known about the endemic transmission of CHIKV. To ascertain the endemic occurrence of CHIKV transmission, we tested blood samples from patients with a non-dengue febrile illness who participated in a prospective cohort study of factory workers in Bandung, Indonesia. From August 2000 to June 2004, and September 2006 to April 2008, 1901 febrile episodes occurred and 231 (12.2% dengue cases were identified. The remaining febrile cases were evaluated for possible CHIKV infection by measuring anti-CHIKV IgM and IgG antibodies in acute and convalescent samples. Acute samples of serologically positive cases were subsequently tested for the presence of CHIKV RNA by RT-PCR and/or virus isolation. A total of 135 (7.1% CHIKV infections were identified, providing an incidence rate of 10.1/1,000 person years. CHIKV infections were identified all year round and tended to increase during the rainy season (January to March. Severe illness was not found and severe arthralgia was not a prominently reported symptom. Serial post-illness samples from nine cases were tested to obtain a kinetic picture of IgM and IgG anti-CHIKV antibodies. Anti-CHIKV IgM antibodies were persistently detected in high titers for approximately one year. Three patients demonstrated evidence of possible sequential CHIKV infections. The high incidence rate and continuous chikungunya cases in this adult cohort suggests that CHIKV is endemically transmitted in Bandung. Further characterization of the circulating strains and surveillance in larger areas are needed to better understand CHIKV epidemiology in Indonesia.

  16. Experimental infection of Hawai'i 'Amakihi (hemignathus virens) with West Nile virus and competence of a co-occurring vector, culex quinquefasciatus: potential impacts on endemic Hawaiian avifauna.

    Science.gov (United States)

    Lapointe, Dennis; Hofmeister, Erik K.; Atkinson, C.T.; Porter, R.E.; Dusek, Robert J.

    2009-01-01

    Introduced mosquito-borne avian disease is a major limiting factor in the recovery and restoration of native Hawaiian forest birds. Annual epizootics of avian pox (Avipoxvirus) and avian malaria (Plasmodium relictum) likely led to the extinction of some species and continue to impact populations of susceptible Hawaiian honeycreepers (Drepanidinae). The introduction of a novel pathogen, such as West Nile virus (WNV), could result in further population declines and extinctions. During September and October 2004, we infected Hawai'i' Amakihi (Hemignathus virens) with a North American isolate of WNV by needle inoculation and mosquito bite to observe susceptibility, mortality, and illness in this endemic passerine, and to determine the vector competence of the co-occurring, introduced mosquito Culex quinquefasciatus. All experimentally infected Hawai'i ;Amakihi became viremic, with a mean titer >10(5) plaque-forming units (PFU)/ml, and they experienced clinical signs ranging from anorexia and lethargy to ataxia. The fatality rate among needle-inoculated Hawai'i' Amakihi (n=16) was 31.3%, but mortality in free-ranging birds is likely to increase due to predation, starvation, thermal stress, and concomitant infections of avian malaria and pox. Surviving Hawai'i' Amakihi seem to clear WNV from the peripheral blood by 7-10 days postinfection (DPI), and neutralizing antibodies were detected from 9 to 46 DPI. In transmission trials, Hawaiian Cx. quinquefasciatus proved to be a competent vector and Hawai'i Amakihi an adequate amplification host of WNV, suggesting that epizootic WNV could readily become an additional limiting factor of some native Hawaiian bird populations.

  17. Soil seed-bank composition reveals the land-use history of calcareous grasslands

    Science.gov (United States)

    Karlík, Petr; Poschlod, Peter

    2014-07-01

    We compared soil seed banks and vegetation of recent (established on abandoned arable fields) and ancient (continuously managed as pastures at least since 1830) calcareous grasslands if there is any impact of former arable field use. The study was carried out in two regions of Southern Germany with well-preserved dry grassland vegetation: the western Jurassic mountains (Kaltes Feld) and the climatically drier eastern part of Southern Germany (Kallmünz). Total number of species in the seed bank was similar in both regions, but species composition partly differed, reflecting phytogeographical differences between the regions. The total number of emerged seedlings showed a large disparity (5457 compared to 2523 seedlings/m2 in Kaltes Feld and Kallmünz, respectively). Though there were differences in seed bank composition and size, we found a uniform pattern of plant traits (affiliation to phytosociological groups, Raunkiaer plant life-forms and seed longevity), which depended on the age of the grassland. The main conclusion is that seed banks in contemporary calcareous grasslands still reflect the history of former land use - in this case arable cultivation, even though it occurred a long time ago (up to 150 years). Indicators of former arable fields are germinable seeds of weeds which have persisted in the soil to the present. By contrast, weedy species are completely absent from the seed banks of ancient grasslands. Soil seed banks of recent grasslands may be of substantial conservation importance because they may store seeds of rare and endangered weed species such as Kickxia spuria, Silene noctiflora and Stachys annua, the majority of which have already gone extinct from the current vegetation of the study sites.

  18. Water relations in grassland and desert ecosystems exposed to elevated atmospheric CO2.

    Science.gov (United States)

    Morgan, J A; Pataki, D E; Körner, C; Clark, H; Del Grosso, S J; Grünzweig, J M; Knapp, A K; Mosier, A R; Newton, P C D; Niklaus, P A; Nippert, J B; Nowak, R S; Parton, W J; Polley, H W; Shaw, M R

    2004-06-01

    Atmospheric CO2 enrichment may stimulate plant growth directly through (1) enhanced photosynthesis or indirectly, through (2) reduced plant water consumption and hence slower soil moisture depletion, or the combination of both. Herein we describe gas exchange, plant biomass and species responses of five native or semi-native temperate and Mediterranean grasslands and three semi-arid systems to CO2 enrichment, with an emphasis on water relations. Increasing CO2 led to decreased leaf conductance for water vapor, improved plant water status, altered seasonal evapotranspiration dynamics, and in most cases, periodic increases in soil water content. The extent, timing and duration of these responses varied among ecosystems, species and years. Across the grasslands of the Kansas tallgrass prairie, Colorado shortgrass steppe and Swiss calcareous grassland, increases in aboveground biomass from CO2 enrichment were relatively greater in dry years. In contrast, CO2-induced aboveground biomass increases in the Texas C3/C4 grassland and the New Zealand pasture seemed little or only marginally influenced by yearly variation in soil water, while plant growth in the Mojave Desert was stimulated by CO2 in a relatively wet year. Mediterranean grasslands sometimes failed to respond to CO2-related increased late-season water, whereas semiarid Negev grassland assemblages profited. Vegetative and reproductive responses to CO2 were highly varied among species and ecosystems, and did not generally follow any predictable pattern in regard to functional groups. Results suggest that the indirect effects of CO2 on plant and soil water relations may contribute substantially to experimentally induced CO2-effects, and also reflect local humidity conditions. For landscape scale predictions, this analysis calls for a clear distinction between biomass responses due to direct CO2 effects on photosynthesis and those indirect CO2 effects via soil moisture as documented here.

  19. Mixed artificial grasslands with more roots improved mine soil infiltration capacity

    Science.gov (United States)

    Wu, Gao-Lin; Yang, Zheng; Cui, Zeng; Liu, Yu; Fang, Nu-Fang; Shi, Zhi-Hua

    2016-04-01

    Soil water is one of the critical limiting factors in achieving sustainable revegetation. Soil infiltration capacity plays a vital role in determining the inputs from precipitation and enhancing water storage, which are important for the maintenance and survival of vegetation patches in arid and semi-arid areas. Our study investigated the effects of different artificial grasslands on soil physical properties and soil infiltration capacity. The artificial grasslands were Medicago sativa, Astragalus adsurgens, Agropyron mongolicum, Lespedeza davurica, Bromus inermis, Hedysarum scoparium, A. mongolicum + Artemisia desertorum, A. adsurgens + A. desertorum and M. sativa + B. inermis. The soil infiltration capacity index (SICI), which was based on the average infiltration rate of stage I (AIRSI) and the average infiltration rate of stage III (AIRS III), was higher (indicating that the infiltration capacity was greater) under the artificial grasslands than that of the bare soil. The SICI of the A. adsurgens + A. desertorum grassland had the highest value (1.48) and bare soil (-0.59) had the lowest value. It was evident that artificial grassland could improve soil infiltration capacity. We also used principal component analysis (PCA) to determine that the main factors that affected SICI were the soil water content at a depth of 20 cm (SWC20), the below-ground root biomasses at depths of 10 and 30 cm (BGB10, BGB30), the capillary porosity at a depth of 10 cm (CP10) and the non-capillary porosity at a depth of 20 cm (NCP20). Our study suggests that the use of Legume-poaceae mixtures and Legume-shrub mixtures to create grasslands provided an effective ecological restoration approach to improve soil infiltration properties due to their greater root biomasses. Furthermore, soil water content, below-ground root biomass, soil capillary porosity and soil non-capillary porosity were the main factors that affect the soil infiltration capacity.

  20. Intensive management in grasslands causes diffuse water pollution at the farm scale.

    Science.gov (United States)

    Peukert, Sabine; Griffith, Bruce A; Murray, Phillip J; Macleod, Christopher J A; Brazier, Richard E

    2014-11-01

    Arable land use is generally assumed to be the largest contributor to agricultural diffuse pollution. This study adds to the growing evidence that conventional temperate intensively managed lowland grasslands contribute significantly to soil erosion and diffuse pollution rates. This is the first grassland study to monitor hydrological characteristics and multiple pollutant fluxes (suspended sediment [SS] and the macronutrients: total oxidized nitrogen-N [TON], total phosphorus [TP], and total carbon [TC]) at high temporal resolution (monitoring up to every 15 min) over 1 yr. Monitoring was conducted across three fields (6.5-7.5 ha) on the North Wyke Farm Platform, UK. The estimated annual erosion rates (up to 527.4 kg ha), TP losses (up to 0.9 kg ha), and TC losses (up to 179 kg ha) were similar to or exceeded the losses reported for other grassland, mixed land-use, and arable sites. Annual yields of TON (up to 3 kg ha) were less than arable land-use fluxes and earlier grassland N studies, an important result as the study site is situated within a Nitrate Vulnerable Zone. The high-resolution monitoring allowed detailed "system's functioning" understanding of hydrological processes, mobilization- transport pathways of individual pollutants, and the changes of the relative importance of diffuse pollutants through flow conditions and time. Suspended sediment and TP concentrations frequently exceeded water quality guidelines recommended by the European Freshwater Fisheries Directive (25 mg L) and the European Water Framework Directive (0.04 mg soluble reactive P L), suggesting that intensively managed grasslands pose a significant threat to receiving surface waters. Such sediment and nutrient losses from intensively managed grasslands should be acknowledged in land management guidelines and advice for future compliance with surface water quality standards. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of