Weak niche partitioning by migrating shorebirds in a single-food-type environment

2019 ◽  
Vol 12 (3) ◽  
pp. 109-117 ◽  
Author(s):  
Ivana Novcic
Keyword(s):  
Sandy Beach ◽  
Niche Partitioning ◽  
Food Type ◽  
Swash Zone ◽  
Semipalmated Sandpiper ◽  
Foraging Niche ◽  
Coexisting Species ◽  
Sand And Gravel ◽  
Selection Of ◽  
Semipalmated Sandpipers

This study examined foraging niche partitioning among coexisting species of shorebirds on a sandy beach dominated by a single food type, Horseshoe Crab ( Limulus polyphemus) eggs, where use of foraging microhabitats of limited variety is temporarily restricted due to tidal cycle. The major goal of the study was to examine whether co-occurring species differed in selection of foraging microhabitats and use of feeding techniques. Ruddy Turnstone ( Arenaria interpres), Red Knot ( Calidris canutus), and Sanderling ( Calidris alba) foraged significantly more on sand and gravel compared to pools and swash zone, Semipalmated Sandpiper ( Calidris pusilla) foraged significantly more on sand and gravel compared to swash zone, but not significantly more compared to pools, while differences in use of microhabitats by Dunlin ( Calidris alpina), and Short-billed Dowitcher ( Limnodromus griseus) were non-significant. Turnstones used digging and turning stones, and pecking significantly more than probing, Semipalmated Sandpipers used pecking significantly more than probing, while all other species used probing significantly more than pecking. Knots and Sanderlings had the highest level of overlap both in use of microhabitats and foraging techniques, while turnstones and dowitchers had the lowest. Ruddy Turnstones were the only birds that used digging and turning stones to obtain food and these two foraging methods seemed to be the most important variables discriminating turnstones from other co-occurring shorebirds. However, despite the slight differences in use of foraging methods and microhabitats by different species, this study documented weak partitioning among shorebirds, particularly between sandpipers and dowitchers. These results indicate that the short-term absence of clear niche partitioning on a local scale may occur in shorebird communities.

scholarly journals Evaluation of the average performance of topcrosses among food and grain type soybean

2003 ◽  
Vol 46 (3) ◽  
pp. 323-332 ◽  
Author(s):  
Gilberto K. Yokomizo ◽  
Natal A. Vello
Keyword(s):  
Breeding Strategy ◽  
Food Type ◽  
Joint Analysis ◽  
Individual Plant ◽  
Vegetable Soybean ◽  
Yield Performance ◽  
Plant Yield ◽  
Average Performance ◽  
Growing Conditions ◽  
Selection Of

The food type soybean (exotic) are, in general, non-adapted to the Brazilian growing conditions. A breeding strategy to develop adapted food type soybean should involve crossing exotic with the available grain type genotypes. We evaluated the performance of topcrosses among food type and grain type soybeans. Best progenies showed different performance rates in each environment and they were not always the same in the different environments and joint analysis of lodging (L), plant height at maturity (PHM) and agronomic value (AV) was essential to avoid selection of plants with good performance for one trait and bad for another.) Piracicaba autumn environment (PA) caused low individual plant yield performance (IPY), and consequently, cultivation was not economically viable in this period. Best progenies presented appropriate trait averages for inclusion in the category of vegetable soybean in all evaluated environments.

scholarly journals EFFECTS OF SEASONAL VARIATIONS ON SANDY BEACH GROUNDWATER TABLE AND SWASH ZONE SEDIMENT TRANSPORT

2014 ◽  
Vol 1 (34) ◽  
pp. 59
Author(s):  
Norasman Othman ◽  
Ahmad Khairi Abd Wahab ◽  
Mohamad Hidayat Jamal
Keyword(s):  
Sediment Transport ◽  
Seasonal Variations ◽  
Sandy Beach ◽  
Groundwater Table ◽  
Swash Zone

scholarly journals Environmental signal shredding on sandy coastlines

2019 ◽  
Vol 7 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Eli D. Lazarus ◽  
Mitchell D. Harley ◽  
Chris E. Blenkinsopp ◽  
Ian L. Turner
Keyword(s):  
Sandy Beach ◽  
Shoreline Change ◽  
Storm Events ◽  
Shoreline Position ◽  
Physical Effects ◽  
Sand And Gravel ◽  
Open Question ◽  
Observational Record ◽  
Coastal Research

Abstract. How storm events contribute to long-term shoreline change over decades to centuries remains an open question in coastal research. Sand and gravel coasts exhibit remarkable resilience to event-driven disturbances, and, in settings where sea level is rising, shorelines retain almost no detailed information about their own past positions. Here, we use a high-frequency, multi-decadal observational record of shoreline position to demonstrate quantitative indications of morphodynamic turbulence – “signal shredding” – in a sandy beach system. We find that, much as in other dynamic sedimentary systems, processes of sediment transport that affect shoreline position at relatively short timescales may obscure or erase evidence of external forcing. This suggests that the physical effects of annual (or intra-annual) forcing events, including major storms, may convey less about the dynamics of long-term shoreline change – and vice versa – than coastal researchers might wish.

scholarly journals EXPERIMENT ON RESPONSE OF SANDY BEACH WITH DIFFERENT CONTENTS OF SAND AND GRAVEL TO WAVES

2016 ◽  
Vol 72 (2) ◽  
pp. I_655-I_660 ◽  
Author(s):  
Akio KOBAYASHI ◽  
Takaaki UDA ◽  
Yasuhito NOSHI ◽  
Takayuki YOSHINO
Keyword(s):  
Sandy Beach ◽  
Sand And Gravel

scholarly journals Seasonal niche differentiation between evolutionary closely related marine bacteria

2020 ◽  
Author(s):  
Adrià Auladell ◽  
Albert Barberán ◽  
Ramiro Logares ◽  
Esther Garcés ◽  
Josep M. Gasol ◽  
...  
Keyword(s):  
Marine Bacteria ◽  
Niche Partitioning ◽  
Environmental Parameters ◽  
Niche Overlap ◽  
Niche Differentiation ◽  
Habitat Filtering ◽  
Coastal Marine ◽  
Class Level ◽  
Nucleotide Divergence ◽  
Selection Of

AbstractBacteria are highly dynamic in marine environments, where they play key biogeochemical roles. Here, we tested how similar the niche of closely related marine bacteria is and what are the environmental parameters modulating their ecological responses in a coastal oligotrophic time series. We further explored how conserved the niche is at broader taxonomic levels. We found that, for certain genera, niche similarity decreases as nucleotide divergence increases between closely related amplicon sequence variants, a pattern compatible with selection of similar taxa through habitat filtering. Additionally, we observed evidence of niche partitioning within various genera shown by the distinct seasonal patterns of closely related taxa. At broader levels, we did not observe coherent seasonal trends at the class level, with the order and family ranks conditioned to the patterns that exist at the genus level. This study explores the coexistence of niche overlap and niche partitioning in a coastal marine environment.

scholarly journals Spatial distribution of macrofauna within a sandy beach on the Caribbean coast of Costa Rica

2018 ◽  
Vol 66 (1-1) ◽  
pp. 176 ◽  
Author(s):  
Jeffrey A. Sibaja-Cordero
Keyword(s):  
Spatial Distribution ◽  
Costa Rica ◽  
Random Distribution ◽  
Sandy Beach ◽  
Niche Partitioning ◽  
Food Resource ◽  
Caribbean Coast ◽  
Tide Level ◽  
The Caribbean ◽  
Mechanical Disturbances

Knowingthe spatial pattern and densities of individuals in apopulation is basic to understand ecology such as their response to environmental gradients.The main goal of the present study is to describe the abundances and distribution of thebenthicfauna in thelower intertidallevelof asandybeach at PacuareReserve, Caribbean Coast, Costa Rica. The count data of five taxa (in 29 cores) was analyzed to determine their spatial distribution. Two species of polychaetes were found: the first, Scolelepis (Scolelepis) squamata (O. F. Mueller, 1806) was common in the center of the beach in an aggregated pattern. The second, Pisionidens indica (Aiyar & Alikunhi, 1940) was present in low densities with a random distribution pattern. Moreover, two isopods were found: Excirolana braziliensis Richardson, 1912 was randomly distributed along the beach while Ancinus brasiliensis Lemos de Castro, 1959 appeared only in two stations. A meiofaunal nemerteanattached tograins of sand was the mostcommon organismin theintertidal zone, showing a clumped pattern. Thepatches ofabundancewithin the beachcould be duetoamorphologicchangethat imposes the influenceof thestrongsurf conditions. Moreover, food resource distribution, niche partitioning or competition within the same tide level could influence the different patterns of distribution found in the sediment among the species. In these unstable sediments, the fauna was limited to few opportunist taxa well adapted to withstand mechanical disturbances.

scholarly journals Swash zone dynamics of a sandy beach with low tide terrace during variable wave and tide conditions

2016 ◽  
Author(s):  
Luis Pedro ALMEIDA ◽  
Rafael ALMAR ◽  
Patrick MARCHESIELLO ◽  
Rachid BENSHILA ◽  
Kevin MARTINS ◽  
...  
Keyword(s):  
Sandy Beach ◽  
Swash Zone

scholarly journals ASPEK PERTUMBUHAN UNDUR-UNDUR LAUT, Hippa adactyla DARI PANTAI BERPASIR KABUPATEN KEBUMEN

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Ali Mashar Dan Yusli Wardiatno
Keyword(s):  
Growth Pattern ◽  
Sustainable Management ◽  
Sandy Beach ◽  
Biological Information ◽  
Swash Zone ◽  
Area Method ◽  
The World ◽  
Biological Component ◽  
Swept Area ◽  
Ecology And Economy

ABSTRAKUndur-undur laut atau mole crab merupakan komponen penting dari komunitas makrobentos di pantaiberpasir terbuka, baik di daerah tropis maupun bermusim empat di seluruh dunia.Undur-undur lautmempunyai fungsi ekonomi dan ekologi.Salah satu jenis undur-undur laut yang banyak dijumpai diIndonesia adalah jenis Hippa adactyla.Karena fungsi ekonomi dan ekologi undur-undur laut pentinguntuk dilestarikan, salah satu informasi penting yang dibutuhkan adalah pola pertumbuhan undurundurlaut.Penelitian dilakukan di Pantai Bocor, Kecamatan Buluspesantren, KabupatenKebumen.Pengambilan sampel undur-undur laut dilakukan setiap bulan dari bulan Maret hingga Mei2012, yang dilakukan dengan metode penyapuan dengan bantuan alat tangkap sorok pada daerahpantai berpasir yang terpengaruh gerakan gelombang (swash zone) (swept area method).Hasilpenelitian menunjukkan bahwa undur-undur laut Hippa adactyla yang tertangkap mempunyai kisaranpanjang karapas antara 15 mm hingga 40 mm, dengan ukuran yang paling banyak tertangkap beradapada selang panjang karapas 24-26 mm.Nisbah kelamin undur-undur laut di lokasi penelitianmendekati 1 (1,035) atau tergolong seimbang, dimana jumlah undur-undur laut jantan relatif seragamdengan undur-undur laut betina.Kondisi ini juga menunjukkan bahwa kondisi populasi undur-undurlaut di lokasi penelitian relatif stabil. Pola pertumbuhan undur-undur laut Hippa adactylaseluruhnya,baik jantan, betina, maupun gabungan, adalah isometrik, artinya pertambahan panjang undur-undurlaut relatifsama dengan pertambahan bobotnya.Kata kunci: Hippa adactyla, pantai berpasir, undur-undur lautABSTRACTMole crabs are one of important biological component among macrobenthos communityinhabiting sandy beach, both in tropic or temperate area all over the world. They playsignificant ecology and economy role in their habitat. One of Indonesian mole crabs is Hippaadactyla. Due to its ecological and economical function of the crab, it is neede to study thepopulation growth pattern for biological information based sustainable management. One ofimportant biological information is growth pattern. The research was conducted in PantaiBocor, Kecamatan Buluspesantren, Kabupaten Kebumen. Sample collections were donemonthly during March – May 2012. Sampling was done by swep area method by means oflocal fishermen gear called sorok along swash zone. The results showed that the carapacelength of collected crabs ranged from 19 – 34 mm, with the highest abundance within range of29 – 30 mm. Female dominated the sex ratio. The F/M ratio was 0.244. The growth pattern ofmale was isometric, while in female it was negative allometric. However, combining datashowed that the growth patern of the population was negative allometric, so its length growsfaster than its weight.Keywords: Hippa adactyla, sandy beach, mole crab, southern part of Jawa

scholarly journals Storm Waves at the Shoreline: When and Where Are Infragravity Waves Important?

2019 ◽  
Vol 7 (5) ◽  
pp. 139 ◽  
Author(s):  
Oliver Billson ◽  
Paul Russell ◽  
Mark Davidson
Keyword(s):  
Deep Water ◽  
Water Wave ◽  
Sandy Beach ◽  
Transport Processes ◽  
Infragravity Waves ◽  
Storm Wave ◽  
Wave Conditions ◽  
Gravel Beaches ◽  
Deep Water Wave ◽  
Sand And Gravel

Infragravity waves (frequency, f = 0.005–0.05 Hz) are known to dominate hydrodynamic and sediment transport processes close to the shoreline on low-sloping sandy beaches, especially when incident waves are large. However, in storm wave conditions, how their importance varies on different beach types, and with different mixes of swell and wind-waves is largely unknown. Here, a new dataset, comprising shoreline video observations from five contrasting sites (one low-sloping sandy beach, two steep gravel beaches, and two compound/mixed sand and gravel beaches), under storm wave conditions (deep water wave height, H0 up to 6.6 m, and peak period, Tp up to 18.2 s), was used to assess: how the importance and dominance of infragravity waves varies at the shoreline? In this previously unstudied combination of wave and morphological conditions, significant infragravity swash heights (Sig) at the shoreline in excess of 0.5 m were consistently observed on all five contrasting beaches. The largest infragravity swash heights were observed on a steep gravel beach, followed by the low-sloping sandy beach, and lowest on the compound/mixed sites. Due to contrasting short wave breaking and dissipation processes, infragravity frequencies were observed to be most dominant over gravity frequencies on the low-sloping sandy beach, occasionally dominant on the gravel beaches, and rarely dominant on the compound/mixed beaches. Existing empirical predictive relationships were shown to parameterize Sig skillfully on the sand and gravel beaches separately. Deep water wave power was found to accurately predict Sig on both the sand and gravel beaches, demonstrating that, under storm wave conditions, the wave heights and periods are the main drivers of infragravity oscillations at the shoreline, with the beach morphology playing a secondary role. The exception to this was the compound/mixed beach sites where shoreline infragravity energy remained low.

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