scholarly journals Unraveling the Seed Dispersal System of an Insular “Ghost” Dragon Tree (Dracaena draco) in the Wild

Author(s):  
Aarón González-Castro ◽  
David Pérez-Pérez ◽  
Javier Romero ◽  
Manuel Nogales
2015 ◽  
Vol 31 (5) ◽  
pp. 385-394 ◽  
Author(s):  
Nitin Sekar ◽  
Raman Sukumar

Abstract:Large animal species are prone to local extirpation, but ecologists cannot yet predict how the loss of megaherbivores affects ecosystem processes such as seed dispersal. Few studies have compared the quantity and quality of seed dispersal by megaherbivores versus alternative frugivores in the wild, particularly for plant species with fruit easily consumed by many frugivorous species. In a disturbed tropical moist forest in India, we examine whether megaherbivores are a major frugivore of two tree species with easily edible, mammal-dispersed fruit. We quantify the relative fruit removal rates of Artocarpus chaplasha and Careya arborea, by the Asian elephant (Elephas maximus) and alternative dispersers. Through focal watches and camera trapping, we found the elephant to be amongst the top three frugivores for each tree species. Furthermore, seed transects under A. chaplasha show that arboreal frugivores discard seeds only a short distance from the parental tree, underscoring the elephant's role as a long-distance disperser. Our data provide unprecedented support for an old notion: megaherbivores may be key dispersers for a broad set of mammal-dispersed fruiting species, and not just fruit inaccessible to smaller frugivores. As such, the elephant may be particularly important for the functional ecology of the disturbed forests it still inhabits across tropical Asia.


Author(s):  
Thecan Caesar-Ton That ◽  
Lynn Epstein

Nectria haematococca mating population I (anamorph, Fusarium solani) macroconidia attach to its host (squash) and non-host surfaces prior to germ tube emergence. The macroconidia become adhesive after a brief period of protein synthesis. Recently, Hickman et al. (1989) isolated N. haematococca adhesion-reduced mutants. Using freeze substitution, we compared the development of the macroconidial wall in the wild type in comparison to one of the mutants, LEI.Macroconidia were harvested at 1C, washed by centrifugation, resuspended in a dilute zucchini fruit extract and incubated from 0 - 5 h. During the incubation period, wild type macroconidia attached to uncoated dialysis tubing. Mutant macroconidia did not attach and were collected on poly-L-lysine coated dialysis tubing just prior to freezing. Conidia on the tubing were frozen in liquid propane at 191 - 193C, substituted in acetone with 2% OsO4 and 0.05% uranyl acetate, washed with acetone, and flat-embedded in Epon-Araldite. Using phase contrast microscopy at 1000X, cells without freeze damage were selected, remounted, sectioned and post-stained sequentially with 1% Ba(MnO4)2 2% uranyl acetate and Reynold’s lead citrate. At least 30 cells/treatment were examined.


2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.


2020 ◽  
Vol 2020 (1) ◽  
pp. 78-81
Author(s):  
Simone Zini ◽  
Simone Bianco ◽  
Raimondo Schettini

Rain removal from pictures taken under bad weather conditions is a challenging task that aims to improve the overall quality and visibility of a scene. The enhanced images usually constitute the input for subsequent Computer Vision tasks such as detection and classification. In this paper, we present a Convolutional Neural Network, based on the Pix2Pix model, for rain streaks removal from images, with specific interest in evaluating the results of the processing operation with respect to the Optical Character Recognition (OCR) task. In particular, we present a way to generate a rainy version of the Street View Text Dataset (R-SVTD) for "text detection and recognition" evaluation in bad weather conditions. Experimental results on this dataset show that our model is able to outperform the state of the art in terms of two commonly used image quality metrics, and that it is capable to improve the performances of an OCR model to detect and recognise text in the wild.


2020 ◽  
Vol 12 (3) ◽  
pp. 189
Author(s):  
Sebastian Gäb

When we were on the subway back from his lecture, I said to Robin: “I’m not sure there actually are any religious fictionalists.” We keep talking about them in papers and lectures, acting as if fictionalism in religion is a real possibility, but to be honest, I haven’t been able to spot one in the wild so far. The only potential candidate who comes to mind is Don Cupitt, who wrote things like: “I still pray and love God, even though I fully acknowledge that no God actually exists.”[1] Perhaps this is as fictionalist as it gets. But then again, Cupitt never explicitly declared himself a fictionalist (at least to my knowledge). Moreover, on other occasions he sounds more like an expressivist than a fictionalist, e.g. when he says: “The Christian doctrine of God just is Christian spirituality in coded form.”[2] So, if there are any actual fictionalists out there, please step forward.[1] Don Cupitt, After God: The Future of Religion (Basic Books, 1997), 85.[2] Don Cupitt, Taking leave of God (SCM Press, 1980), 14.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Elly Lestari Rustiati ◽  
Priyambodo Priyambodo ◽  
Yanti Yulianti ◽  
Eko Agus Srihanto ◽  
Dian Neli Pratiwi ◽  
...  

Way Kambas National Park (WKNP) is home of five protected big mammals including sumatran elephants.  It shares its border with 22 of 37 villages surrounding the national park.  Understanding their existence in the wild is a priority, and  wildlife genetics is a crucially needed. Besides poaching and habitat fragmentation, wildlife-human conflict is one big issue.  Elephant Training Center (ETC) in WKNP is built for semi in-situ conservation effort on captive sumatran elephants that mainly have conflict histories with local people.  Participative observation and bio-molecular analysis were conducted to learn the importance of captive Sumatran elephant for conservation effort.  Through captive sumatran elephants, database and applicable methods are expected to be developed supporting the conservation of their population in the wild.  Participative observation and molecular identification was carried on captive sumatran elephants in ETC, WKNP under multiple year Terapan grant of Ministry of Research and Technology Higher Education, Indonesia. Gene sequence and cytological analyses showed that the captive sumatran elephants are closely related and tend to be domesticated.  Translocation among ETC to avoid inbreeding, and maintaining the captive sumatran elephant as natural as possible are highly recommended. Developing genetic database can be a reference for both captive and wild sumatran elephants.


2008 ◽  
Vol 1 (1) ◽  
pp. 7-18
Author(s):  
Luciane Lopes de Souza

Biotic or abiotic processes of seed dispersal are important for the maintenance of the diversity, and for the natural regeneration in tropical forests. Ichthyochory is one of the fundamental mechanisms for seed dispersal in flooded environments, as the “igapó” forests. A study on the ichthyochory of the igapós was conducted at Amanã Sustainable Development Reserve, in the middle Solimões river, from June 2002 to September 2004. Monthly samples of frugivorous fish were taken, with the main fishing gears used locally. Guts of 1,688 fish caught were examined. The main species were Myloplus rubripinnis (29.21%), Hemiodus immaculatus (18.96%),Colossoma macropom um (16.23%) and Mylossoma duriventre (16.05%). The diet was made of vegetables (fruits, leave and flowers), and animals (arthropods). 53.02% of all fish caught ingested fruits. The total number of intact seeds in the stomachs and intestines were 8,069 and 5,763 respectively. About 61.9% of the Brycon melanopterus (matrinchão), 46.34% of the Brycon amazonicus (mamuri) and 30.22% of M . rubripinnis (parum ) analysed had intact seeds in their guts. Seeds of Nectandra amazonum and Genipa spruceana ingested proved to be more viable than those non-ingested by fish. The high rates of frugivory, the presence of intact seeds in the guts of fish and the greater viability of ingested seeds all suggest that these animals are important seed dispersors in the “igapó” forests of Amanã Reserve.


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