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عنوان فارسی مقاله:
شکارگری دانه و حذف از مدفوع در یک اکوسیستم خشک
عنوان انگلیسی مقاله:
Seed predation and removal from faeces in a dry ecosystem
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Seed dispersal can be a complex multi-stage process (Vander Wall & Longland 2004, 2005; Vander Wall, Forget, Lambert, & Hulme 2005; Vander Wall, Khun, & Beck 2005) where the initial dispersal movement is usually obvious (e.g. wind, frugivorous animals), but subsequent movements are often not so evident. The potential fate of seeds deposited in faeces is immediate germination, dormancy, mixing into the litter by the action of trampling and faeces decomposition (Malo & Suárez 1995a, 1995b; Dai 2000; Campos, Mangeaud, Borghi, de los Rios, & Giannoni 2011), or removal by animals (Brown & Heske 1990; Price & Joyner 1997; Hulme & Benkman 2002). In arid and semiarid ecosystems, faecal material can be an unfavourable environment for seed survival and seedling establishment for three reasons. First, faeces can be exposed to harsh environmental conditions, such as extreme temperatures and radiation, which produce seed desiccation (Borchert & Tyler 2010). Second, seed aggregation in faeces may attractseed predators(Janzen 1982; Chapman 1989; LoGiudice & Ostfeld 2002). Third, if germination occurs, seedling competition can be strong (e.g. Loiselle 1990). Survival ofseedsin faeces and seedling establishment has been associated with a second movement away from the point of deposition after primary dispersal (Vander Wall, Khun, & Gworek 2005). Therefore, seed removal from faeces appears as a relevant stage in the seed dispersal process which is worth assessing to understand the dynamics of seedling establishment and plant recruitment. Nearly all existing studies that address secondary movement of seeds from faeces come from temperate and tropical systems (Vander Wall, Khun, & Beck 2005; Vander Wall, Khun, & Gworek 2005; D’hondt, Bossuyt, Hoffmann, & Bonte 2008; Manzano, Azcárate, Peco, & Malo 2010 and references therein), while in dry ecosystems we know almost nothing about this process. Studies from the tropics point out that dung beetles, ants and rodents are the major secondary seed dispersers (Vander Wall, Khun, & Beck 2005). Rodents have been historically considered seed predators, but certain species with scatter-hoarding behaviour (Wenny 1999; Feer & Forget 2002; Giannoni et al. 2013) play roles as both predators and dispersers(Theimer 2005). Ants also play a dual role because, although they consume many seeds, they may also disperse some of them (in trails and refuse dumps), thusinfluencing seed-bank dynamics and promoting seedling establishment ofsome plantspeciesin tropical forests(Levey & Byrne 1993; Passos & Oliveira 2002). In the Monte desert, some studies have studied the removal of Prosopis flexuosa fruits from under the trees’ cover by small rodents, but there is no information on removal of seeds from faeces. We know that the sigmodontine rodent Graomys griseoflavus transports an important number of propagules, but they are left mainly in larders and later depredated, whereas Eligmodontia typus scatter-hoards propagules and leaves intact seeds removed from the fruits (Giannoni et al. 2013). Both speciesmove fruits and store seeds atshort distances(200 cm; Campos, Giannoni, Taraborelli, & Borghi 2007). Regarding ants, eleven species have been recorded exploiting P. flexuosa fruits, most of them remove the mesocarp in situ, and only Acromyrmex and Pheidole species were capable of carrying fruit segments (Milesi & Lopez de Casenave 2004). Abiotic factors and ecological interactions can affect the fate of seeds in faeces. Attraction to high density of seeds clumped in faeces (Traveset 1990; Hulme 1994) and granivore satiation (Janzen 1971) influence the choices of secondary seed removers. Additionally, abiotic characteristics of the sites where faeces are deposited,such as vegetation structure (Christianini & Galetti 2007) and local availability of alternative food (Bermejo, Traveset, & Wilson 1998; LoGiudice 2001), affect animal foraging and the probability of a second dispersal event of seeds from faeces. P. flexuosa is a keystone tree species in the Monte desert. It produces abundant fruits that accumulate on the ground, representing a source of food for a wide variety of organisms. Cattle may transport, disperse, and redistribute a large number of Prosopis seeds. However, survival of seedlings in dung is virtually negligible (Campos et al. 2008, 2011), and therefore a second movement may represent another chance for seeds to survive. Our main goal is to investigate the fate of seeds in faeces and to identify the particular ecological conditions that promote a second movement of seeds. To achieve this goal, we evaluate the magnitude of seed predation and removal from faeces by rodents and ants. Moreover, we assessthe simultaneousinfluence that different microhabitats and availability of P. flexuosa fruits have on seed removal and predation. Using a field experiment with simulated cattle faeces, we aimed at answering the following questions: (1) Do rodents and ants differentially remove and depredate seeds found in faeces? (2) Does the microhabitat where the faeces are deposited affect removal and predation of seeds? (3) Does availability of P. flexuosa fruits influence removal and predation of seeds found in faeces? Regarding the last two questions, we expect to find: (a) lower seed removal and in situ predation on seeds located in faeces lying on bare soil,
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کلمات کلیدی:
Seed Predation | Seedbuzz www.seedbuzz.com › Knowledge Center › Research Articles Seed predation, a ubiquitous phenomenon in tropical rainforests, is an important factor of plant recruitment and forest regeneration. Although seed predation ... Seed Predation by Animals - Annual Reviews www.annualreviews.org/doi/pdf/10.1146/annurev.es.02.110171.002341 by DH Janzen - 1971 - Cited by 1974 - Related articles Many plants suffer very heavy pre- and/or post-dispersal seed predation by animals. A few exemplary studies (2,18,38,52,74,87, 106, 110, 111, 124,. 140, 161 ... Seed Predation www2.nau.edu/~gaud/bio300w/sdprd.htm Consumption of flowers and developing ovules influences seed input to, and, distribution in, the seed bank. Such predispersal seed predation has the potential ... [PDF]Predispersal Seed Predation, Postdispersal Seed Predation and ... digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1002&context=bioscilouda by SM Louda - 1990 - Cited by 94 - Related articles Predispersal Seed Predation, Postdispersal Seed. Predation and Competition in the Recruitment of. Seedlings of a Native Thistle in Sandhills Prairie. Svata M. Uncoupling the Effects of Seed Predation and Seed Dispersal by ... journals.plos.org/plosone/article?id=10.1371/journal.pone.0042869 by X Arnan - 2012 - Cited by 7 - Related articles Aug 7, 2012 - As many other interactions, seed dispersal by animals involves costs (seed predation) and benefits (seed dispersal), the balance of which ... Pre-Dispersal Seed Predation in a Species-Rich Forest Community ... journals.plos.org/plosone/article?id=10.1371/journal.pone.0143040 by Y Xu - 2015 - Related articles Nov 17, 2015 - Pre-dispersal seed predation (PDSP) is commonly observed in woody plants, and recognized as a driver of seed production variability that is ... Searches related to Seed predation seed predation representative species what seed are the nashville predators what animals eats seeds animals that eat nuts and seeds granivore examples granivore animals granivore definition what’s the difference between a standing defense and an induced defense?
