scholarly journals Sampling of parasitoid Hymenoptera: influence of the height on the ground

2020 ◽  
Vol 78 ◽  
pp. 19-31
Author(s):  
Ricardo Chan-Canché ◽  
Horacio Ballina-Gómez ◽  
Jorge Leirana-Alcocer ◽  
Santiago Bordera ◽  
Alejandra González-Moreno
Keyword(s):  
Fixed Effects ◽  
Sampling Method ◽  
Deciduous Forest ◽  
Ground Level ◽  
Representative Species ◽  
Family Level ◽  
Adequate Sampling ◽  
A Site ◽  
Trap Placement ◽  
Malaise Traps

Parasitoid hymenopterans are a highly diverse group of insects; therefore, the choice of an adequate sampling method becomes important to achieve a representative species richness of a site. The aim of this work is to evaluate the size and diversity of parasitoids in relation to the height of the Malaise trap placement above the ground of a low deciduous forest from Yucatan, Mexico. Parasitoids were collected from September to October 2015, using three Malaise traps at ground level and other three located right above the others, leaving no space between them, at a height of 1.5 m. The collected specimens were identified at family level. A total of 4083 parasitoids belonging to 31 families were collected, representing 93% of the sample’s completeness, according to Jack 1 estimator; with differences in richness and abundance between trap heights according to rarefaction and fixed effects multifactorial ANOVA, respectively. Bethylidae, Braconidae and Ichneumonidae were the most abundant families. Besides, when analyzing the differences of each family by separate, there were significant results for Bethylidae, Diapriidae and Ichneumonidae with more individuals in the traps at ground level than in the raised ones. In a further analysis, the effect of body size on the capture height was observed. The specimens of larger size belonging to the families Bethylidae, Sphecidae, Sclerogibbidae and Evaniidae were more collected at ground level, on the other hand, the larger sized Ichneumonidae were collected at raised level.

Geotechnical Investigation, Field Load Test and Analysis of Full-Scale Bored Pile

2015 ◽  
Vol 813-814 ◽  
pp. 1126-1130
Author(s):  
G. Kesavan ◽  
S.S. Chandrasekaran
Keyword(s):  
Tamil Nadu ◽  
Ground Level ◽  
Maximum Load ◽  
Field Investigation ◽  
Complex Problem ◽  
Load Test ◽  
Bored Pile ◽  
Economical Design ◽  
Pile Load Test ◽  
A Site

The maximum load carrying capacity of bored piles is a complex problem because it is a function of a number of factors, these factors include methods of soil exploration, ground water condition, types of grading of concrete, quantity and quality of concrete. The knowledge of Geotechnical test is important for the most economical design of the piles. This paper describes some important aspects of field investigation, design and construction of in-situ bored pile foundation, field pile load test of experience gained from the construction of the pile at a site in Aathoor in Tamil Nadu, India. The site was fully sandy soil from existing ground level. The design of bored pile under axial compression was done using Empirical formula, pile load test and by using PLAXIS 2D software. Results were compared with vertical load and settlement in this site.

scholarly journals Effects of Malaise trap spacing on species richness and composition of terrestrial arthropod bulk samples

2020 ◽  
Author(s):  
D Steinke ◽  
TWA Braukmann ◽  
L Manerus ◽  
A Woodhouse ◽  
V Elbrecht
Keyword(s):  
Species Richness ◽  
Field Experiments ◽  
Collection Efficiency ◽  
Malaise Trap ◽  
Number Of Factors ◽  
Large Numbers ◽  
Set Up ◽  
Taxonomic Groups ◽  
A Site ◽  
Malaise Traps

AbstractThe Malaise trap has gained popularity for assessing diverse terrestrial arthropod communities because it collects large samples with modest effort. A number of factors that influence collection efficiency, placement being one of them. For instance, when designing larger biotic surveys using arrays of Malaise traps we need to know the optimal distance between individual traps that maximises observable species richness and community composition. We examined the influence of spacing between Malaise traps by metabarcoding samples from two field experiments at a site in Waterloo, Ontario, Canada. For one experiment, we used two trap pairs deployed at weekly increasing distance (3m increments from 3 to 27 m). The second experiment involved a total of 10 traps set up in a row at 3m distance intervals for three consecutive weeks.Results show that community similarity of samples decreases over distance between traps. The amount of species shared between trap pairs shows drops considerably at about 15m trap-to-trap distance. This change can be observed across all major taxonomic groups and for two different habitat types (grassland and forest). Large numbers of OTUs found only once within samples cause rather large dissimilarity between distance pairs even at close proximity. This could be caused by a large number of transient species from adjacent habitat which arrive at the trap through passive transport, as well as capture of rare taxa, which end up in different traps by chance.

Honey Mesquite Canopy Responses to Single Winter Fires: Relation to Herbaceous Fuel, Weather and Fire Temperature

1998 ◽  
Vol 8 (4) ◽  
pp. 241 ◽  
Author(s):  
RJ Ansley ◽  
DL Jones ◽  
TR Tunnell ◽  
BA Kramp ◽  
PW Jacoby
Keyword(s):  
Moisture Content ◽  
Warm Season ◽  
Ground Level ◽  
Weather Conditions ◽  
Fuel Moisture ◽  
Fire Temperature ◽  
A Site ◽  
Fuel Moisture Content ◽  
Honey Mesquite ◽  
Warm Season Grasses

Honey mesquite (Prosopis glandulosa Torr.) canopy responses to fire were measured following 20 single winter fires conducted in north Texas. Weather conditions during the fires, understory herbaceous fine fuel (fine fuel) amount and moisture content, fire temperature at 0 cm, 10-30 cm and 1-3 m above ground, and canopy responses were compared. Ten fires occurred on a site where fine fuel was a mixture of cool and warm season grasses (mixed site). The other 10 fires occurred on a site dominated by warm season grasses (warm site). When both sites were included in regressions, peak fire temperature at all heights was positively related to fine fuel amount. Fine fuel amount, fine fuel moisture content, air temperature (AT) and relative humidity (RH) affected fire temperature duration in seconds over 100°C (FTD100) at 1-3 m height, but not at ground level. Mesquite percent above-ground mortality (topkill) increased with increasing fine fuel amount, decreasing fuel moisture content, increasing AT, and decreasing RH. Percent foliage remaining on non-topkilled (NTK) trees was inversely related to fine fuel amount and AT, and positively related to fine fuel moisture content. Effect of fire on mesquite topkill and foliage remaining of NTK trees was strongly affected by RH at the warm site (r2 = 0.92 and 0.82, respectively), but not at the mixed site. This difference was due to RH affecting fuel moisture content (and subsequently fire behavior) to a greater degree at the warm than at the mixed site, because of the lower green tissue content in warm site grasses at the time of burning. Under adequate fine fuel amounts to carry a fire, mesquite canopy responses to fire (i.e., topkill vs, partial canopy defoliation) were largely determined by AT and RH conditions during the fire. This has implications if the management goal is to preserve the mesquite overstory for a savanna result instead of topkilling all trees. Two substudies were conducted during 3 of the fires. Substudy 1 determined mesquite response to fire in 2 plots with different understory herbaceous fuel loads (5,759 vs. 2,547 kg/ha) that were burned under under similar weather conditions. Mesquite topkill was 81% and 11% in the high and low fuel fires, respectively. Under similar weather conditions, fine fuel was an important factor in affecting mesquite responses to fire. However, as demonstrated in the main study, under a variety of weather conditions, AT and RH influenced mesquite response to fire as much or more than did fine fuel. Substudy 2 compared response of mesquite plants with abundant and dry subcanopy fine fuel (3252 kg/ha; fuel moisture 10.4%), or sparse and green subcanopy fuel (1155 kg/ha; fuel moisture 25.9%) to a high intensity fire. All trees were topkilled, including those with low subcanopy fuel, probably from convection heat generated from herbaceous fuel in interspaces between trees. In support of this conclusion, thermocouple data from all 20 fires indicated that canopy responses were more related to fire temperature at 1-3 m than at lower heights. This suggests that the topkill mechanism was due to convective heat within the canopy rather than a girdling effect of fire at stem bases.

Analysis of a Population Sampling Method for the Lodgepole Needle Miner in Canadian Rocky Mountain Parks

1952 ◽  
Vol 84 (10) ◽  
pp. 316-321 ◽  
Author(s):  
R. W. Stark
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Sampling Method ◽  
Rocky Mountain ◽  
Fixed Time ◽  
Forest Stand ◽  
Population Sampling ◽  
Adequate Sampling ◽  
History Of ◽  
External Feeding

General.—The purpose of this paper is to analyse a sampling method devised to assess larval populations in an outbreak of the lodgepole needle miner, Recurvaria milleri Busck (Busck 1914, Hopping 1945).The problem of developing an adequate sampling method is intimately concerned with the life-history of the insect, the region of the outbreak and the nature of the forest stand in which the outbreak occurs. In sampling most defoliator populations the problem is made more difficult by external feeding and wandering habits, hence it is usually done in some relatively inactive stage at a fixed time. de Gryse (1934) describes the problems inherent in sampling these insects. The needle miner, however, is fixed in its location for most of its life-cycle and is therefore readily obtainable for study. The problem here is reduced to a statistical one, that of obtaining an acceptable sample i.e. within suitable error limits with due regard for existing variables.

scholarly journals Using Malaise traps to sample ground beetles (Coleoptera: Carabidae)

2005 ◽  
Vol 137 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Michael D. Ulyshen ◽  
James L. Hanula ◽  
Scott Horn
Keyword(s):  
Ground Beetles ◽  
Pitfall Traps ◽  
Material Type ◽  
Abundance And Diversity ◽  
Trap Placement ◽  
Malaise Traps

Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and “trap-shy” species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002).

A Method of Language Sampling

1993 ◽  
Vol 17 (1) ◽  
pp. 169-203 ◽  
Author(s):  
Jan Rijkhoff ◽  
Dik Bakker ◽  
Kees Hengeveld ◽  
Peter Kahrel
Keyword(s):  
Sample Size ◽  
Internal Structure ◽  
Sampling Method ◽  
Linguistic Diversity ◽  
Sampling Strategy ◽  
Language Sampling ◽  
The World ◽  
Adequate Sampling

In recent years more attention is being paid to the quality of language samples in typological work. Without an adequate sampling strategy, samples may suffer from various kinds of bias. In this article we propose a sampling method in which the genetic criterion is taken as the most important: samples created with this method will reflect optimally the diversity of the languages of the world. On the basis of the internal structure of each genetic language tree a measure is computed that reflects the linguistic diversity in the language families represented by these trees. This measure is used to determine how many languages from each phylum should be selected, given any required sample size.

scholarly journals Hoverfly (Diptera: Syrphidae) assemblage of an oak–hornbeam in the Merlino Wood Natural Reserve and implications for its conservation

2020 ◽  
Vol 8 ◽  
Author(s):  
Umberto Maritano
Keyword(s):  
Northern Italy ◽  
Habitat Conservation ◽  
Po Plain ◽  
Good Preservation ◽  
Community Interest ◽  
Natural Reserve ◽  
Lowland Forests ◽  
A Site ◽  
First Time ◽  
Malaise Traps

Merlino Wood is a typical oak–hornbeam forest in the Po Plain hydrographic region. It is one of the few remaining lowland forests in Northern Italy and is a Regional Natural Reserve and a Site of Community Interest (code IT1160010). This is the first survey on hoverflies in the study area and they act as bioindicators to assess habitat conservation. Sampling was performed with three Malaise traps and an entomological net. A total of 61 species of Syrphidae were recorded between March and October 2019. Three of the species observed are considered to be under threat in Europe, three species have been recorded for the first time in Piedmont and Heringia latitarsis (Egger, 1865) has been recorded for the first time in Northern Italy. The Syrph the Net analysis has been used to assess habitat conservation. It shows good preservation of xylosaprophagous species, while the conservation conditions of other larval trophic categories are poor.

scholarly journals Relación Entre Biomasa Aérea Y Producción Primaria Neta Con Las Variaciones Estacionales De Precipitaciones Y Temperaturas En Pastizales Del Sur De La Provincia De Córdoba

2017 ◽  
Vol 13 (5) ◽  
pp. 117
Author(s):  
Cerutti, A., N. Mónaco ◽  
M. J. Rosa y V. Santa.
Keyword(s):  
Fixed Effects ◽  
Net Primary Productivity ◽  
Ground Level ◽  
Constant Weight ◽  
A Value ◽  
Natural Pasture ◽  
Randomized Design ◽  
Natural Grasslands ◽  
Completely Randomized Design ◽  
The Town

Natural grasslands of the planet are very important reservoirs of flora and fauna that provide various ecosystem services benefits. To maintain and improve their condition, it is necessary to study them and understand their composition and functioning as well as their evolution over time. In the present work the influence of climatic variables, temperature and rainfall on the aerial biomass behavior and the net primary productivity of a pasture were analyzed. For this purpose, a natural pasture was located on the banks of the Chocancharava River, in the town of Río Cuarto. Monthly sampling (September 2014 - August 2015) was carried out, cutting aerial biomass at ground level with tusar scissors and collecting biomass and mulch in 10 quadrants of 0.5 x 0.5 m (0.25 m2) and dried in stove to constant weight. This material was separated into compartments: green (BV), dry (BS) and mulch (BM) to determined the available biomass. For statistical analysis, a completely randomized design (DCA) of fixed effects with Infostat program was used. The highest contribution of BV was in summer months, 4262 kg / ha of 8772 kg / ha corresponding to the total cycle. The highest BS was determined in winter with 2715 kg / ha of the total 6663 kg / ha. The litter presented a behavior similar to the BV, with the highest peaks in summer months 2478 kg / ha of 6004 kg / ha. The PPN presented a marked spring increase. Adding the positive increases in monthly PPN, a value of 1206.6 kg / ha * year was determined. Considering that higher temperatures and rainfall are recorded in summer (average 22 ° C and 422 mm), it could be assert that these variables would explain a significant part of the variability in the total aerial biomass production of the pasture.

scholarly journals Green roof and ground-level invertebrate communities are similar and are driven by building height and landscape context

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jacinda R Dromgold ◽  
Caragh G Threlfall ◽  
Briony A Norton ◽  
Nicholas S G Williams
Keyword(s):  
Native Species ◽  
Green Space ◽  
Ground Level ◽  
Green Roofs ◽  
Vegetation Types ◽  
Invertebrate Community ◽  
Invertebrate Communities ◽  
Surrounding Environment ◽  
Native Grassland ◽  
Family Level

Abstract Green roofs are increasingly promoted for urban biodiversity conservation, but the value of these novel habitats is uncertain. We aimed to test two hypotheses: (i) green roofs can support comparable invertebrate family and order richness, composition and abundances to ground-level habitats and (ii) green roofs planted with native species from local habitats will support a richer invertebrate community at family and order level than other green roofs. We sampled the invertebrate community on green roofs dominated by native grassland or introduced succulent species in Melbourne, Australia, and compared these to the invertebrate community in ground-level sites close by, and sites with similar vegetation types. The only significant differences between the invertebrate communities sampled on green roofs and ground-level habitats were total abundance and fly family richness, which were higher in ground-level habitats. Second hypothesis was not supported as invertebrate communities on green roofs supporting a local vegetation community and those planted with introduced Sedum and other succulents were not detectably different at family level. The per cent cover of green space surrounding each site was consistently important in predicting the richness and abundance of the invertebrate families we focussed on, while roof height, site age and size were influential for some taxa. Our results suggest that invertebrate communities of green roofs in Melbourne are driven largely by their surrounding environment and consequently the effectiveness of green roofs as invertebrate habitat is highly dependent on location and their horizontal and vertical connection to other habitats.

Incidence and risk of central nervous system (CNS) metastases as a site of first recurrence in patients (pts) with HER2-positive (HER2+) breast cancer treated with adjuvant trastuzumab (T).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 609-609
Author(s):  
Erin Macrae Olson ◽  
Mahmoud Abdel-Rasoul ◽  
Christina Sing-Ying Wu ◽  
Joseph Maly ◽  
Xueliang Jeff Pan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Fixed Effects ◽  
Disease Recurrence ◽  
Cns Metastases ◽  
Adjuvant Trastuzumab ◽  
Her2 Breast Cancer ◽  
Increased Risk ◽  
Significant Difference ◽  
First Recurrence ◽  
A Site

609 Background: T is the mainstay of adjuvant therapy in pts with HER2+ breast cancer. CNS disease as the site of first relapse after exposure to adjuvant T has been reported, although the overall incidence and relative risk (RR) of this remains unclear. We performed an up-to-date meta-analysis to determine the risk of CNS metastases as the first site of recurrence in pts with HER2+ breast cancer who received adjuvant T. Methods: Pubmed databases were searched for articles from 1966 to 2011. Abstracts presented at the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium were also searched for relevant clinical trials. Eligible studies include randomized trials with adjuvant T administered for 1 year in pts with HER2+ breast cancer who reported CNS metastases as first site of disease recurrence. Statistical analyses were conducted to calculate the summary incidence, RR, and 95% CIs using fixed effects inverse variance models. Results: A total of 9,020 pts were included. The incidence of CNS metastases as first site of disease recurrence in HER2+ pts receiving adjuvant T was 2.56% (95% CI 2.07% to 3.01%) compared to 1.94% (95% CI: 1.54% to 2.38%) in HER2+ pts who did not receive adjuvant T. The RR of CNS as first site of relapse in T-treated pts was 1.35 (95% CI 1.02 to 1.78, p=0.038) compared with control arms without T therapy. In subgroup analyses, there was no significant difference in CNS incidence or risk between pts treated with concurrent versus sequential T (p=0.29), weekly versus every 3 week T (p=0.56), and no difference in the T groups between studies due to median follow up time in years (p=0.68). No evidence of publication bias was observed (Q=1.78; P=0.62; I2 = 0.0%). Conclusions: This is the largest report to date demonstrating that adjuvant T is associated with an increased risk of CNS metastases as a site of first recurrence in HER2+ breast cancer pts.

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