scholarly journals Spatial distribution and seasonal fluctuations ofDrosophilaon Santa Catalina Island with an emphasis on the repleta species group

2014 ◽  
Author(s):  
Joyce Y Kao ◽  
Sergey V Nuzhdin
Keyword(s):  
Spatial Distribution ◽  
Species Abundance ◽  
Field Studies ◽  
Species Group ◽  
Small Island ◽  
Drosophila Pseudoobscura ◽  
Seasonal Fluctuations ◽  
Unknown Species ◽  
Santa Catalina Island ◽  
Drosophila Mettleri

Santa Catalina Island is a small island off the coast of southern California and for its modest size harbors several species of flies from theDrosophilagenus. We performed an island-wide survey ofDrosophilaspecies to ascertain which species were endemic to the island and where they were most abundant. In doing so, we have assembled useful sampling information for researchers who wish to conduct field studies on Santa Catalina Island. From this survey, we determined thatDrosophila hamatofila,Drosophila mainlandi, andDrosophila mettleriwere the prominent repleta species on the island. Other repleta species encountered includedDrosophila mojavensisandDrosophila wheeleri. Non-repleta species sighted on the island includeDrosophila melanogaster,Drosophila pseudoobscura,Drosophila simulans, and an unknown species not seen before on the island. Additionally, we performed seasonal collections at two locations on the island and observed that species abundance and composition at these two sites vary between seasons. One of the seasonal sites was sampled in two consecutive summer seasons, which revealed that species composition had shifted between years, but relative abundances were approximately the same.

Duplex DNA barcoding allows accurate species determination of morphologically similar limpets (Patella spp.) from non-destructive sampling

2016 ◽  
Vol 97 (7) ◽  
pp. 1479-1482 ◽  
Author(s):  
Thomas J. Ashton ◽  
Meriem Kayoueche-Reeve ◽  
Andrew J. Blight ◽  
Jon Moore ◽  
David M. Paterson
Keyword(s):  
Dna Barcoding ◽  
Species Abundance ◽  
Microscopic Analysis ◽  
Cost Effective ◽  
Field Studies ◽  
Similar Species ◽  
Species Determination ◽  
Destructive Sampling ◽  
Species Specific ◽  
Non Destructive

Accurate discrimination of two morphologically similar species of Patella limpets has been facilitated by using qPCR amplification of species-specific mitochondrial genomic regions. Cost-effective and non-destructive sampling is achieved using a mucus swab and simple sample lysis and dilution to create a PCR template. Results show 100% concurrence with dissection and microscopic analysis, and the technique has been employed successfully in field studies. The use of highly sensitive DNA barcoding techniques such as this hold great potential for improving previously challenging field assessments of species abundance.

scholarly journals Self–organized instability in complex ecosystems

2002 ◽  
Vol 357 (1421) ◽  
pp. 667-681 ◽  
Author(s):  
Ricard V. Solé ◽  
David Alonso ◽  
Alan McKane
Keyword(s):  
Rare Species ◽  
Scaling Law ◽  
Species Abundance ◽  
Field Studies ◽  
Species Number ◽  
Neotropical Forests ◽  
Species Abundances ◽  
Long Tails ◽  
Critical Boundary ◽  
Species Area

Why are some ecosystems so rich, yet contain so many rare species? High species diversity, together with rarity, is a general trend in neotropical forests and coral reefs. However, the origin of such diversity and the consequences of food web complexity in both species abundances and temporal fluctuations are not well understood. Several regularities are observed in complex, multispecies ecosystems that suggest that these ecologies might be organized close to points of instability. We explore, in greater depth, a recent stochastic model of population dynamics that is shown to reproduce: (i) the scaling law linking species number and connectivity; (ii) the observed distributions of species abundance reported from field studies (showing long tails and thus a predominance of rare species); (iii) the complex fluctuations displayed by natural communities (including chaotic dynamics); and (iv) the species–area relations displayed by rainforest plots. It is conjectured that the conflict between the natural tendency towards higher diversity due to immigration, and the ecosystem level constraints derived from an increasing number of links, leaves the system poised at a critical boundary separating stable from unstable communities, where large fluctuations are expected to occur. We suggest that the patterns displayed by species–rich communities, including rarity, would result from such a spontaneous tendency towards instability.

scholarly journals Challenges of ecological monitoring: estimating population abundance from sparse trap counts

2011 ◽  
Vol 9 (68) ◽  
pp. 420-435 ◽  
Author(s):  
Natalia Petrovskaya ◽  
Sergei Petrovskii ◽  
Archie K. Murchie
Keyword(s):  
Population Size ◽  
Numerical Integration ◽  
Spatial Data ◽  
Population Distribution ◽  
Species Abundance ◽  
Ecological Monitoring ◽  
Field Studies ◽  
Pest Species ◽  
Population Size Estimates ◽  
Size Estimates

Ecological monitoring aims to provide estimates of pest species abundance—this information being then used for making decisions about means of control. For invertebrate species, population size estimates are often based on trap counts which provide the value of the population density at the traps' location. However, the use of traps in large numbers is problematic as it is costly and may also be disruptive to agricultural procedures. Therefore, the challenge is to obtain a reliable population size estimate from sparse spatial data. The approach we develop in this paper is based on the ideas of numerical integration on a coarse grid. We investigate several methods of numerical integration in order to understand how badly the lack of spatial data can affect the accuracy of results. We first test our approach on simulation data mimicking spatial population distributions of different complexity. We show that, rather counterintuitively, a robust estimate of the population size can be obtained from just a few traps, even when the population distribution has a highly complicated spatial structure. We obtain an estimate of the minimum number of traps required to calculate the population size with good accuracy. We then apply our approach to field data to confirm that the number of trap/sampling locations can be much fewer than has been used in many monitoring programmes. We also show that the accuracy of our approach is greater that that of the statistical method commonly used in field studies. Finally, we discuss the implications of our findings for ecological monitoring practice and show that the use of trap numbers ‘smaller than minimum’ may still be possible but it would result in a paradigm shift: the population size estimates should be treated probabilistically and the arising uncertainty may introduce additional risk in decision-making.

Spatial distribution and seed mass variation of Strophostyles helvola along Lake Erie

1996 ◽  
Vol 74 (8) ◽  
pp. 1313-1321 ◽  
Author(s):  
Mary Yanful ◽  
M. A. Maun
Keyword(s):  
Spatial Distribution ◽  
Intraspecific Competition ◽  
Lake Erie ◽  
Seed Mass ◽  
Field Studies ◽  
Sandy Beaches ◽  
Recurrent Event ◽  
Limiting Factor ◽  
Probability Of Survival ◽  
The Waves

Field studies were conducted to determine the survival, seed-mass variability, and reproductive strategies of wild bean, Strophostyles helvola (L.) Ell., plants on the foredunes at Port Burwell Provincial Park along Lake Erie. In spring, a large number of seedlings were found on the drift-line (area of beach where detritis deposits are cast on shore by the waves) and a small number both on the lakeward (mid-beach) and landward (high-beach) ends of the drift-line. Plants growing on the mid-beach were larger and produced a significantly greater number of heavier seeds than those on the drift-line. However, during late fall and winter months, a large proportion of these seeds were moved by wind and wave action to the drift-line. Intraspecific competition was not a limiting factor on the mid-beach; however, on the drift-line, the number of seeds per plant decreased significantly with an increase in density of plants from about 1 to 140/m2, suggesting that intraspecific competition may be an important limiting factor in seed production per plant. The mean mass per seed significantly declined over the growing season of S. helvola. There was a significant increase in mean seed mass with increasing pod size. Seeds in the centre of a pod were significantly heavier than those at the proximal and distal ends of a pod. Strophostyles helvola is able to flourish in the constantly shifting shoreline beach habitats along Lake Erie owing to two main factors. First, it is able to fully utilize the highly variable beach microhabitats and maintain high total reproductive output per square metre. Second, since burial in sand is a major recurrent event on sandy beaches, the high variability in seed mass will be of adaptive significance because seedlings from large seeds will not only be able to emerge from greater depths of burial in sand but also will have greater probability of survival under burial conditions. Keywords: seed mass, plant location, Strophostyles helvola, seed position, spatial distribution.

scholarly journals Extensive horizontal exchange of transposable elements in the Drosophila pseudoobscura group

2018 ◽  
Author(s):  
Tom Hill ◽  
Andrea J. Betancourt
Keyword(s):  
Horizontal Transfer ◽  
Species Group ◽  
Data Availability ◽  
Drosophila Pseudoobscura ◽  
Chromosome Size ◽  
Short Read ◽  
Short Read Archive ◽  
Ncbi Short Read Archive ◽  
Mobile Component ◽  
Different Levels

AbstractWhile the horizontal transfer of a parasitic element can be a potentially catastrophic, it is increasingly recognized as a common occurrence. The horizontal exchange, or lack of exchange, of TE content between species results in different levels of divergence among a species group in the mobile component of their genomes. Here, we examine differences in the TE content of the Drosophila pseudoobscura species group. We identify several putative horizontal transfer events, and examine the role that horizontal transfer plays in the spread of TE families to new species and the homogenization of TE content in these species. Despite rampant exchange of TE families between species, we find that both TE content differs hugely across the group, likely due to differing activity of each TE family and differing suppression of TEs due to divergence in Y chromosome size, and its resulting effects of TE regulation. Overall, we show that TE content is highly dynamic in this species group, and that it plays a large role in shaping the differences seen between species.Data availabilityAll data used in this study (summarized in table S1) is freely available online through the NCBI short read archive (NCBI SRA: ERR127385, SRR330416, SRR330418, SRR1925723, SRR330426, SRR330420, SRR330423, SRR617430-74). All genomes used are either available through flybase.org or popoolation.at.

scholarly journals Thermophilous fringe communities as an indicator of vegetation changes: a case study of the “Murawy Dobromierskie” steppe reserve (Poland)

2015 ◽  
Vol 40 (1) ◽  
pp. 77-104
Author(s):  
Tomasz Szygendowski ◽  
Andrzej Brzeg
Keyword(s):  
Field Studies ◽  
Species Group ◽  
Vegetation Changes ◽  
Collective Group ◽  
Moss Layer ◽  
Fringe Communities ◽  
Notable Increase ◽  
Systematic Group ◽  
Geranion Sanguinei

Abstract In this paper, changes of the non-forest xerothermic vegetation of the “Murawy Dobromierskie” steppe reserve which occurred in the period 1993-2012 are examined. The material comprises 50 relevés, of which 43 date from 2012 and the other 7 - from 1993. Reléves were arranged in 5 analytic tables. A synoptic table was also compiled, and for each syntaxonomical species group distinguished, values of the cover coefficient (C), the collective group share index (G), and the systematic group value (D) were estimated and compared. On the basis of the obtained results, a significant decline in abundancy and/or constancy was observed within the following groups: Ch. Artemisietea vulgaris, Ch. Cirsio-Brachypodion pinnati, Ch. Festuco-Brometea, Ch. Geranion sanguinei, Ch. Koelerio-Corynephoretea, and Ch. Origanetalia and Trifolio-Geranietea sanguinei, whereas for the taxa of the Rhamno-Prunetea, a notable increase in the share of the reserve vegetation was recorded. A sizeable expansion of the moss layer was also observed in this period. The results are discussed with special regard to differences in the methodical background of both field studies.

scholarly journals Kinetic modeling of nucleation experiments involving SO<sub>2</sub> and OH: new insights into the underlying nucleation mechanisms

2009 ◽  
Vol 9 (1) ◽  
pp. 1273-1300
Author(s):  
H. Du ◽  
F. Yu
Keyword(s):  
Thermodynamic Properties ◽  
Atmospheric Aerosols ◽  
Experimental Studies ◽  
Lower Troposphere ◽  
Field Studies ◽  
H2so4 Concentration ◽  
Atmospheric Nucleation ◽  
Unknown Species ◽  
Nucleation Mechanisms ◽  
Order Of Magnitude

Abstract. Nucleation is an important source of atmospheric aerosols which have significant climatic and health implications. Despite intensive theoretical and field studies during past decades, the dominant nucleation mechanism in the lower troposphere remains to be mysterious. Several recent laboratory studies on atmospheric nucleation may shed light on this important problem. However, the most interesting finding from those studies was based on the H2SO4 concentration whose accuracy has not yet been evaluated by any other methods. Moreover, the threshold H2SO4 concentration needed to reach the same degree of nucleation reported by two separate nucleation studies varies by about one order of magnitude. In this study, we apply a recently updated kinetic nucleation model to study the nucleation phenomena observed in those recent experiments. We show that the H2SO4 concentration can be estimated with a higher level of accuracy with the kinetic model by constraining the simulated particle size distributions with observed ones. We find that the H2SO4 concentration was underestimated in those studies by a factor of ~2 to 4. More importantly, by comparing the derived thermodynamic properties associated with the nucleation process, we conclude that different unknown species may participate in the two separate nucleation experimental studies, which may explain the large difference in the reported threshold H2SO4 concentration. Although the unknown species involved has yet to be identified, the derived values of thermodynamic properties can serve as a valuable guideline for the search of their chemical identities using advanced quantum-chemical approaches.

scholarly journals Distribusi Spasial, Sumber Pencemaran, dan Kajian Risiko Ekologi Polisiklik Aromatik Hidrokarbon (PAH) dalam Sedimen Pesisir di Pulau Bintan, Indonesia

2019 ◽  
Vol 20 (2) ◽  
pp. 271
Author(s):  
Deny Yogaswara ◽  
Ita Wulandari ◽  
Khozanah Khozanah ◽  
Edward Edward ◽  
Dede Falahudin
Keyword(s):  
Spatial Distribution ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Ecological Risk ◽  
Aromatic Hydrocarbons ◽  
Surface Sediments ◽  
Biological Effects ◽  
Sediment Quality ◽  
Diagnostic Methods ◽  
Small Island ◽  
Polycyclic Aromatic

ABSTRACTBintan Island is the small island in the Riau Archipelago which borders Singapore and Malaysia. Its water is crossed by international shipping lines. Therefore, water quality in this area is potentially polluted by marine activities. The present study aimed to evaluate the concentration, spatial distribution, and assessment of ecological risks of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from selected coastal water of Bintan. Surface sediments in this study were extracted by using the ultrasonic system and determined with GCMS. The data were visualized with ArGIS software for spatial distribution mapping, applied ratio diagnostic methods for the source of PAH contamination, and assess their ecological risk based on sediment quality guidelines. The results showed PAHs concentrations ranged from below the method detection limit (<DL) to 13.492 ng.g−1(dry weight) with the highest concentration of PAHs were detected at TJU 1 station as much as 13.492 ng.g-1. As many as seven types of PAHs were identified in Bintan water, they were Naphthalene (two rings), Fluorene and Anthracene (three rings); fluoranthene, Pyrene, Benzo (a) Pyrene and Chrysene (five rings). Based on diagnostic ratios, the sources of PAHs in this coastal area were mainly from pyrogenic origins. Ecological risk assessment has shown that the average value of ∑10 PAH in Bintan waters (5.855 ng.g-1) is lower than the corresponding ERL, ERM, TEL, and PEL value indicating that the adverse biological effects of PAHs are generally low.Keywords: Polycyclic Aromatic Hydrocarbons (PAHs), Distribution, Pollution, Bintan WatersABSTRAKPulau Bintan merupakan pulau kecil di Kepulauan Riau yang berbatasan langsung dengan negara Singapura dan Malaysia serta perairannya dilintasi oleh jalur pelayaran internasional sehingga potensi pencemaran dari aktivitas di laut sangat tinggi. Penelitian ini bertujuan untuk mengukur konsentrasi, distribusi spasial, sumber asal pencemaran dan analisis resiko lingkungan senyawa PAH dalam sedimen permukaan di perairan pesisir Pulau Bintan. Sedimen permukaan diekstraksi dengan sistem ultrasonik dan dianalisa akhir dengan GCMS. Data senyawa PAH diolah dengan software ArGIS untuk membuat peta distribusi spasial, dianalisa dengan metode diagnosa rasio untuk mengetahui sumber pencemarnya dan dibandingkan dengan nilai baku mutu sedimen untuk mengkaji resiko ekologinya. Hasil analisis di setiap stasiun sampling di Muara Pengudang dan Tanjung Uban menunjukkan konsentrasi Total PAH (TPAH) berkisar antara < limit deteksi alat (1 ngg-1) sampai 13,492 ng.g-1 berat kering dengan konsentrasi tertinggi terdeteksi di stasiun TJU 1 yaitu sebesar 13,492 ng.g-1.  Sebanyak tujuh jenis senyawa PAH teridentifikasi di perairan Bintan ini diantaranya Naphthalene, (dua cincin benzene), Fluorene dan Anthracene (tiga cincin benzene); Fluoranthene, Pyrene, Benzo (a) Pyrene, dan Chrysene (empat cincin benzene). Berdasarkan analisa diagnosa rasio, sumber pencemaran PAH di perairan pesisir Bintan adalah berasal dari kombinasi antara sumber pirogenik. Analisis resiko lingkungan menunjukkan nilai rata-rata ∑10 PAH di perairan Bintan (5,855 ngg-1) masih rendah dibandingkan nilai ERL, ERM, TEL dan PEL, hal tersebut mengindikasikan bahwa efek biologis senyawa PAH secara umum rendah.Kata kunci: Polisiklik Aromatik Hidrokarbon (PAH), Sebaran, Pencemaran, Perairan Bintan

Description and ecology of a new species of the cricket genus Endecous (Orthoptera: Grylloidea: Phalangopsidae) in the speleological province of Arcos-Pains-Doresópolis, Southeastern Brazil

Zootaxa ◽  
2020 ◽  
Vol 4821 (2) ◽  
pp. 305-332
Author(s):  
RODRIGO ANTÔNIO CASTRO-SOUZA ◽  
VITOR GABRIEL PEREIRA JUNTA ◽  
RODRIGO LOPES FERREIRA
Keyword(s):  
Spatial Distribution ◽  
New Species ◽  
Species Abundance ◽  
Bilateral Symmetry ◽  
Environmental Stability ◽  
Southeastern Brazil ◽  
Mining Activities ◽  
Key Factors ◽  
Horizontal Projection ◽  
A New Species

A new cricket species of the genus Endecous Saussure, 1878 is described in the present work found in the speleological province of Arcos-Pains-Doresópolis, which belongs to the limestone group Bambuí, Brazil. Moreover, the spatial distribution of the new species was related to the species Eidmanacris sp., which co-occurs with the former in several caves. Relationships between species abundance and horizontal projection, number of entrances and environmental stability of the caves where these species coexist were evaluated. The presence of bilateral symmetry in individuals of Endecous painensis n. sp. perhaps due to environmental stress caused by mining activities surrounding the cave was also tested. Endecous crickets are commonly observed in the caves, for which the preference by distinct microhabitats and generalist strategies may be key factors explaining colonization and segregation in relation to other cricket species in subterranean habitats. The generalist lifestyle of the here described species may attenuate the effects environmental stresses over development.

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