Fire history of a prairie/forest boundary: more than 250 years of frequent fire in a North American tallgrass prairie

Questions: Most modern fire‐prone landscapes have experienced disruptions of their historic fire regimes. Are the primary tallgrass prairies of the Flint Hills reflective of a history of continuous fire occurrence? Did fire frequency, severity, size and seasonality change in connection with changes in land use? Has fire occurrence been related to drought conditions? Location: Edges of Cross Timbers forest stands at the Tallgrass Prairie Preserve (TGPP) in the Flint Hills of Osage County, Oklahoma, USA. Methods: Cross‐sections of 76 Quercus stellata were collected from Cross Timbers stands at or near the grassland edge in the TGPP. Dendrochronological methods were used to identify years of formation for tree rings and fire scars. Superposed epoch analysis was used to evaluate the effect of drought conditions on fire occurrence. Results: Fires were recorded in 46.6% of the years between 1729 and 2005. In 41 cross‐sections at one site, the mean fire interval between 1759 and 2003 was 2.59 years, with fire interval decreasing from a mean fire interval of 3.76 years in the early part of the record to 2.13 years in modern times. No extended periods without fire were recorded in the study area. Drought conditions had no significant effect on fire occurrence. Conclusions: In contrast with many fire‐prone landscapes worldwide, the prairies of the Flint Hills have experienced no recent fire suppression or exclusion. Changes in fire frequency mark transitions in land use, primarily from being traditionally used by Native Americans to being managed for cattle production.     

Grasshoppers (Orthoptera: Acrididae) select vegetation patches in local‐scale responses to foliar nitrogen but not phosphorus in native grassland

Abstract Key elements such as nitrogen (N) and phosphorus (P) are often limiting relative to the nutritional needs of herbivores that feed on them. While N often limits insect herbivores in natural terrestrial ecosystems, the effect of P is poorly studied in the field, even though compelling hypotheses from the ecological stoichiometry literature predict its importance. We evaluated small‐scale spatial distributions of, and herbivory by, grasshoppers among neighboring plots that vary in foliar‐N and ‐P in tallgrass prairie. Grasshopper densities were 67% greater in N‐fertilized plots but detected no effect to grasshopper densities from P‐fertilizer. Leaf damage to the dominant grass Andropogon gerardii was 32% greater in N‐fertilized plots, but no response to foliar‐P was detected. Herbivore damage to a common forb, goldenrod (Solidago missouriensis), was not strongly linked by fertilizer treatments, although there was increased leaf damage in N‐fertilizer treatments when no P was applied (a significant N × P interaction). Under field conditions at local scales, we conclude that spatially heterogeneous distributions of grasshoppers are primarily affected by foliar‐N in host plants with little evidence that P‐levels contribute to the spatial patterns.     

Response of grasshoppers (Orthoptera: Acrididae) to livestock grazing in southeastern Arizona: differences between seasons and subfamilies

Summary Grasshopper densities were compared between grazed and ungrazed semidesert grassland sites in southeastern Arizona. Bouteloua-dominated perennial grass cover was about 1.5 times greater on the livestock exclosure. Grasshoppers were 3.7 times more abundant on the protected area in the summers of 1983 and 1984, when dominant species were grass-feeding members of the subfamily Gomphocerinae. In fall 1984, grasshoppers were 3.8 times more common on the grazed site, when dominants were mainly herb-feeders in the subfamily Melanoplinae. These results indicate important seasonal and taxonomic differences in the responses of grasshoppers to the activities of vertebrate grazers.     

Developmental specialization and geographic structure of host plant use in a polyphagous grasshopper, Schistocerca emarginata (=lineata) (Orthoptera: Acrididae)

Host plant use and availability were determined in early nymphal and adult-stage Schistocerca emarginata (=lineata) (Orthoptera: Acrididae) populations at six localities in Texas, USA. Early instar nymphal populations were feeding almost exclusively on either Ptelea trifoliata (Rutaceae) or Rubus trivialis (Rosaceae). This study represents the first demonstration of a geographic structure of host plant specificity in a polyphagous grasshopper. Recognizing this geographic structure required investigations of both developmental and geographical variation in host plant use. Nymphal diet breadths were significantly less than adult diet breadths at four of six localities and smaller overall when pooled nymphal and adult diet breadths were compared among sites. Neither restricted nymphal mobility nor host plant availability accounted for the observed differences in host plant use between developmental stages and among localities. Evidence suggests that the differences in host use among populations are due to host-plant-associated genetic differentiation. Received: 4 June 1998 / Accepted: 10 March 1999     

Importance of dietary nitrogen and carbohydrates to survival, growth, and reproduction in adults of the grasshopper Ageneotettix deorum (Orthoptera: Acrididae)

Key demographic traits in insect herbivores (survival, growth, and egg production) are often responsive to variation in diet quality, especially to dietary nitrogen (N) levels. Soluble carbohydrates may also be limiting. Using defined diets under controlled laboratory conditions, we examined survival, growth, and egg production in response to a range of diet qualities in adult females of a grass-feeding grasshopper Ageneotettix deorum (Scudder). Diets varied factorially within naturally occurring ranges of total N (1–7%) and carbohydrate (4–27%) levels. N concentrations significantly impacted weight gain, egg production rate, the elapsed time until the first egg pod, and the time between the first and second egg pod. These responses were typically quadratic in nature with a maximum response near 4–5% total N. The rate of pod production rather than number of eggs per pod best explained changes in reproductive rate. Dietary carbohydrate levels seldom exerted a significant impact on demographic parameters except when interacting with N on survival, egg weight, and the period between egg pods. Clearly, factors that alter the availability of quality diet, especially total N levels, can contribute to demographic responses in A. deorum. Received: 5 August 1996 / Accepted: 26 April 1997     

Responses of Mediterranean Plant Species to different fire frequencies in Garraf Natural Park (Catalonia,Spain): field observations and modelling predictions.

Dynamics of the coexisting Mediterranean species Pinus halepensis, Quercus coccifera, Erica multiflora, Rosmarinus officinalis, Cistus albidus, C. salviifolius and Ampelodesmos mauritanica, with contrasted life history traits have been studied under different fire scenarios, following two approaches: a) field survey in areas with three different fire histories (unburned for the last 31 years, once burned in 1982, and twice burned in 1982 and 1994), and b) simulations with different fire recurrence using the FATE vegetation model. We compared observed abundance in the field survey to simulation outputs obtained from fire scenarios that mimicked field fire histories. Substantial mismatching did not occur between field survey and simulations. Higher fire recurrences were associated with an increase in the resprouting Ampelodesmos grass, together with a decrease in Pinus abundance. Resprouting shrubs did not show contrasting changes, but trends of increase in Quercus and decrease in Erica were observed. The seeders Rosmarinus and Cistus achieved maximum abundance at intermediate fire recurrence. We also performed ten 200 year simulations of increasing fire recurrence with average times between fires of 100, 40, 20, 10, and 5 years. A scenario without fire was also simulated. High fire recurrence produces an increase in Ampelodesmos, a grass which is becoming dominant in the area, and a small increase in Erica, but Quercus abundance decreases and Pinus disappears. Rosmarinus and Cistus abundance peaks at intermediate fire frequencies. When comparing these simulations to those in which Ampelodesmos was excluded, we found that the absence of the grass only increased Cistus occurrence in the community, this effect being more important at frequent fire recurrence. The study suggests that simple models based on life history traits may be useful in interpreting plant community dynamics in Mediterranean ecosystems that are greatly influenced by differences in the fire regime.     

Host usage and seasonal activity patterns of Ixodes kingi and I. sculptus (Acari: Ixodidae) nymphs in a Colorado prairie landscape, with a summary of published North American host records for all life stages.

We examined host usage and seasonal activity patterns of the nymphal stage of the ticks Ixodes kingi and I. sculptus within a prairie rodent community in north-central Colorado. Ixodes kingi was commonly encountered on both northern grasshopper mice (Onychomys leucogaster) and thirteen-lined ground squirrels (Spermophilus tridecemlineatus), whereas I. sculptus frequently infested S. tridecemlineatus but was absent from O. leucogaster. Low numbers of ticks of both species were collected from deer mice (Peromyscus maniculatus) and Ord's kangaroo rats (Dipodomys ordii). Nymphal loads of I. kingi and I. sculptus increased dramatically on commonly infested rodent species from spring (May-June) to summer (July-August). Further, rodents trapped on prairie-dog towns tended to experience increased nymphal loads of I. kingi (O. leucogaster, S. tridecemlineatus) but decreased loads of I. sculptus (S. tridecemlineatus) following plague epizootics among prairie dog populations. A summary of published North American host records revealed that I. kingi has been recorded from humans, domestic animals (cat, dog), 17 species of carnivores, 40 species of rodents, and four species of lagomorphs, and that I. sculptus has been recorded from humans, domestic animals (cat, dog, goat), 13 species of carnivores, 34 species of rodents, and three species of lagomorphs. In accordance with our observations from Colorado, I. kingi commonly has been found to infest heteromyid and murid rodents (such as grasshopper mice), whereas I. sculptus most frequently has been collected from ground-dwelling sciurid rodents, especially Spermophilus ground squirrels. The potential roles of I. kingi and I. sculptus as enzootic vectors of human pathogens, particularly the agents of tularemia (Francisella tularensis), Q fever (Coxiella burnetii), and Colorado tick fever (CTF virus), are discussed.     

Metabolic costs of avian flight in relation to flight velocity: a study in Rose Coloured Starlings (Sturnus roseus, Linnaeus)

The metabolic costs of flight at a natural range of speeds were investigated in Rose Coloured Starlings (Sturnus roseus, Linnaeus) using doubly labelled water. Eight birds flew repeatedly and unrestrained for bouts of 6 h at speeds from 9 to 14 m s⁻¹ in a low-turbulence wind tunnel, corresponding to travel distances between 200 and 300 km, respectively. This represents the widest speed range where we could obtain voluntarily sustained flights. From a subset of these flights, data on the wing beat frequency (WBF) and intermittent flight behaviour were obtained. Over the range of speeds that were tested, flight costs did not change with velocity and were on an average 8.17±0.64 W or 114 W kg⁻¹. Body mass was the only parameter with a significant (positive) effect on flight costs, which can be described as EE_f=0.741 M ^0.554. WBF changed slightly with speed, but correlated better with body mass. Birds showed both types of intermittent flight, undulating and bounding, but their frequencies did not systematically change with flight speed.     

The existence of two species of Euceraphis (Homoptera: Aphididae) on birch in Western Europe, and a key to European and North American species of the genus

Abstract. Aphids formerly regarded as Euceraphis punctipennis (Zetterstedt) are distinguished as two species, E.punctipennis and E.betulae (Koch), on the basis of cytological and morphological differences. E.punctipennis is primarily associated with Betula pubescens Ehrh., and E. betulae with B.pendula Roth. Seasonal variations in morphometrics, pigmentation and development of wax glands in the two species are described and compared. A key to European and North American species of Euceraphis is provided.     

Trichuris odocoileus sp. n. (Nematoda: Trichuridae) from white-tailed deer, Odocoileus virginianus, in southeastern U.S., and a key to trichurids in North American ruminants

A new species of Trichuris from the cecum of white-tailed deer, Odocoileus virginianus, from the southeastern United States, is characterized herein. Males had spicules 2.20 to 3.05 mm long with bluntly rounded tips, an ejaculatory duct equal to or slightly longer than the vas deferens, and a spinous spicular sheath with an expansion near its center. Females had a spinous vulva, usually not everted, a loop in the oviduct just before it opened into the uterus, and a slightly curved posterior portion. Trichuris odocoileus was differentiated from T. lani , a species described in Russia which is most like T. odocoileus, by 1) possessing a spicular sheath with a central expansion, 2) greater size with longer ejaculatory duct and vas deferens, 3) slightly larger eggs, and 4) the unique loop in the oviduct. Trichuris odocoileus constitutes the 6th species of Trichuris recovered from North American ruminants. A key is provided to facilitate differentiation of the six species.     

A study of genetic distances and variability in several species pf the gemis Ctenomys (Rodentia: Octodontidae) with special references to a probable causal role of chromosomes in speciation

Genetic variability measured by allozymic electrophoresis has been studied in several species of the subterranean rodent genus Ctenomys (Octodontidae). The study was carried out with the main purpose of analysing a special group known as the 'Corrientes group' which inhabits the province of Corrientes in Argentina. The members of the group are, with high probability, isolated reproductively due to their karyotypic differences diploid numbers are between 42 and 70). To evaluate whether the chromosomal differences were the causes of speciation or if they arose a posteriori, we compared the level of the genetic distance among taxa within the orrientes group with all those measured between intraspecific populations in Ctenomys . The results indicate that the distances among the populations of the Corrientes group are at or below the level of those measured among traspecific populations in Ctenomys . Thus, it is unlikely that genetic differentiation triggered speciation. It is shown that this low level of genetic differentiation is not in contradiction with the high levels expected for species originating from one of the possible mechanisms of chromosomal speciation named, chromosomal transilience. Although for geographical reasons it seems obviousthat gene flow is precluded among the members of the Corrientes group, the Slatkin method for estimating Nm values was also used. Because high values of Nm exist but no isolation by distance could be detected, it is suggested that reproductive and geographical isolation are very ecent. Finally, analysis of population variability suggests that the high levels of heterozygosity observed (a) can be explained by the population structure, and (b) are within the range of expected values if bottlenecks have occurred in the recent history of the Corrientes group. As a general conclusion, the results indicate that in the Corrientes group the genetic data support a putative causal role for chromosomes in speciation.     

A new key for the species of Ateuchus Weber (Coleoptera: Scarabaeidae: Scarabaeinae) occurring in Mexico,with a description of the first North American inquiline species from a rodent burrow (Rodentia: Geomydae) and new distribution records

The first Ateuchus Weber (Scarabaeinae) species, A. tuza sp. nov., from a rodent burrow from North America is described. Diagnostic characters are presented; photographs of an adult male and illustrations of male genitalia are included. A key for all known Mexican Ateuchus Weber species is provided. Ateuchus hornai (Balthasar) is revalidated. New distribution records from Mexico and Central America are reported.     

Rapid response of a long-lived species to improved water and grazing management: The case of the European pond turtle (Emys orbicularis) in the Camargue,France

Among human activities, the effect of habitat management by grazing on population viability is ambiguous. Indeed, beneficial effects of grazing are expected by maintaining open meadows, but overgrazing is supposed to increase mortality by trampling. Grazing has been shown to negatively impact the survival of European pond turtle (Emys orbicularis) in the Camargue. Consequently, a new management plan was defined. We investigated the consequences of this management using capture–recapture methods to estimate variations of population sizes in this managed site and a control site over a 17 years period. Results show an increase of the number of adults and juveniles on the managed site after the management change. Our results suggest that improved water management with flooding in autumn provided better hibernation conditions, and that reduced grazing intensity in autumn/winter likely decreased the risk of trampling. Population size significantly increased in less than 4 years following the management change, probably by the relaxation of density-dependence. It is an original result for a long lived-species supposed to have an important time of resilience to perturbations.     

Contributions to the faunistics and bionomics of Staphylinidae (Coleoptera) in northeastern North America: discoveries made through study of the University of Guelph Insect Collection, Ontario, Canada

Staphylinidae (Rove Beetles) from northeastern North America deposited in the University of Guelph Insect Collection (Ontario, Canada) were curated from 2008-2010 by the first author. The identification of this material has resulted in the recognition of thirty-five new provincial or state records, six new Canadian records, one new record for the United States and two new records for eastern Canada. All records are for subfamilies other than Aleocharinae and Pselaphinae, which will be treated in future publications as collaborative projects. Range expansions of ten exotic species to additional provinces and states are reported. The known distributions of each species in northeastern North America are summarized and presented as maps, and those species with a distinctive habitus are illustrated with color photographs. Genitalia and/or secondary sexual characters are illustrated for those species currently only identifiable on the basis of dissected males. The majority of the new records are in groups that have been recently revised, demonstrating the importance of curation and local insect surveys to the understanding of biodiversity, even for taxa and areas considered 'relatively well-known'.     

A case study of stakeholder perspective and experience with wild American ginseng (Panax quinquefolius) conservation efforts in Pennsylvania, U.S.A.: limitations to a CITES driven, top-down regulatory approach

Following its inclusion in Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the harvest, sale and trade of wild ginseng (Panax quinquefolius) for international commerce has been restricted by law in Pennsylvania since the late 1980s. Since then, exports from the state have declined driving the need to better understand the impact of CITES listing and related state and federal laws. Between 2004 and 2010, we conducted a mixed-methods study in Pennsylvania of stakeholder perspectives on state and federal government conservation efforts and experiences relating to enforcement of harvest and trade restrictions. Results from a survey, key informant interviews, and facilitated group discussions indicate widespread support for ginseng conservation efforts but, not with the CITES driven, top-down regulatory approach. It was widely asserted that ginseng stewardship has been, and will continue to be, governed by personal experience, family teachings, and industry norms and not CITES driven restrictions per se. Moreover, study participants were unable to cite instances where prosecution for ginseng-related “crimes” had occurred within their networks and most believed laws are an ineffective deterrent to “bad behavior.” This emic is externally validated by the fact that agency enforcement is constrained by limited personnel and jurisdictional boundaries, not least of which is an inability to enforce on private lands in the state. These findings suggest that a CITES driven regulatory approach has limitations in actually conserving wild ginseng in Pennsylvania, and suggests that this approach should be complemented by stakeholder supported “bottom-up” partnerships involving greater stakeholder participation, such as government-sponsored or supported ginseng planting programs to counter over-exploitation by collectors and/or extirpation resulting from habitat loss.     

The centipede genus Eupolybothrus Verhoeff, 1907 (Chilopoda: Lithobiomorpha: Lithobiidae) in North Africa, a cybertaxonomic revision, with a key to all species in the genus and the first use of DNA barcoding for the group

The centipede genus Eupolybothrus Verhoeff, 1907 in North Africa is revised. A new cavernicolous species, Eupolybothruskahfi Stoev & Akkari, sp. n., is described from a cave in Jebel Zaghouan, northeast Tunisia. Morphologically, it is most closely related to Eupolybothrusnudicornis (Gervais, 1837) from North Africa and Southwest Europe but can be readily distinguished by the long antennae and leg-pair 15, a conical dorso-median protuberance emerging from the posterior part of prefemur 15, and the shape of the male first genital sternite. Molecular sequence data from the cytochrome c oxidase I gene (mtDNA-5' COI-barcoding fragment) exhibit 19.19% divergence between Eupolybothruskahfi and Eupolybothrusnudicornis, an interspecific value comparable to those observed among four other species of Eupolybothrus which, combined with a low intraspecific divergence (0.3-1.14%), supports the morphological diagnosis of Eupolybothruskahfi as a separate species. This is the first troglomorphic myriapod to be found in Tunisia, and the second troglomorph lithobiomorph centipede known from North Africa. Eupolybothrusnudicornis is redescribed based on abundant material from Tunisia and its post-embryonic development, distribution and habitat preferences recorded. Eupolybothruscloudsley-thompsoni Turk, 1955, a nominal species based on Tunisian type material, is placed in synonymy with Eupolybothrusnudicornis. To comply with the latest technological developments in publishing of biological information, the paper implements new approaches in cybertaxonomy, such as fine granularity XML tagging validated against the NLM DTD TaxPub for PubMedCentral and dissemination in XML to various aggregators (GBIF, EOL, Wikipedia), vizualisation of all taxa mentioned in the text via the dynamically created Pensoft Taxon Profile (PTP) page, data publishing, georeferencing of all localities via Google Earth, and ZooBank, GenBank and MorphBank registration of datasets. An interactive key to all valid species of Eupolybothrus is made with DELTA software.     

Diversity of management practices required to ensure conservation of rare and locally threatened plant species in grasslands: a case study at a regional scale (Lorraine, France)

The Lorraine region, in northeast France, harbours 77 protected plantspecies whose main localities are in grasslands. About 80% of them are very rareor rare (less than 15 localities) in that territory and are threatened by changes inagriculture. These species occur in a large range of grassland habitats,reflecting variability of climatic, hydrological and edaphic parameters, butalso of agricultural practices. A more precise analysis of managementrequirements was carried out for seven of these species, Euphorbiapalustris, Aster amellus, Pulsatillaalba, Carex hordeistichos, Thalictrumminus ssp. majus, Botrychiummatricariifolium and Ophioglossum vulgatum, whichwere represented on a triangle whose corners correspond to grazing, cutting andno or very low exploitation. It confirmed the large diversity of managementpractices required to ensure conservation of rare and threatened grassland plantspecies, even at a local level. These appropriate conservation measures havetherefore to be carried out or, at least, monitored by specialized natureconservation organizations.     

Using a single tablet daily to treat latent tuberculosis infection in Brazil: bioequivalence of two different isoniazid formulations (300 mg and 100 mg) demonstrated by a sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry method in a randomised,crossover study

The recommended treatment for latent tuberculosis (TB) infection in adults is a daily dose of isoniazid (INH) 300 mg for six months. In Brazil, INH was formulated as 100 mg tablets. The treatment duration and the high pill burden compromised patient adherence to the treatment. The Brazilian National Programme for Tuberculosis requested a new 300 mg INH formulation. The aim of our study was to compare the bioavailability of the new INH 300 mg formulation and three 100 mg tablets of the reference formulation. We conducted a randomised, single dose, open label, two-phase crossover bioequivalence study in 28 healthy human volunteers. The 90% confidence interval for the INH maximum concentration of drug observed in plasma and area under the plasma concentration vs. time curve from time zero to the last measurable concentration “time t” was 89.61-115.92 and 94.82-119.44, respectively. The main limitation of our study was that neither adherence nor the safety profile of multiple doses was evaluated. To determine the level of INH in human plasma, we developed and validated a sensitive, simple and rapid high-performance liquid chromatography-tandem mass spectrometry method. Our results showed that the new formulation was bioequivalent to the 100 mg reference product. This finding supports the use of a single 300 mg tablet daily strategy to treat latent TB. This new formulation may increase patients’ adherence to the treatment and quality of life.