Seed Survival in the Palm Astrocaryum standleyanum: Evidence for Dependence upon its Seed Dispersers

Biotropica ◽  
1989 ◽  
Vol 21 (1) ◽  
pp. 50 ◽  
Author(s):  
N. Smythe
Keyword(s):  
Seed Survival ◽  
Astrocaryum Standleyanum ◽  
Seed Dispersers

Influence of chaff and chaff lines on weed seed survival and seedling emergence in Australian cropping systems

2020 ◽  
pp. 1-22
Author(s):  
Michael J. Walsh ◽  
Annie E. Rayner ◽  
Annie Rutledge ◽  
John C. Broster
Keyword(s):  
Cropping Systems ◽  
Seedling Emergence ◽  
Field Studies ◽  
Wild Oat ◽  
Weed Seed ◽  
Weed Species ◽  
Environment Effect ◽  
Seed Survival ◽  
Cropping Seasons ◽  
Rigid Ryegrass

Abstract Chaff lining and chaff tramlining are harvest weed seed control (HWSC) systems that involve the concentration of weed seed containing chaff material into narrow (20 to 30 cm) rows between or on the harvester wheel tracks during harvest. These lines of chaff are left intact in the fields through subsequent cropping seasons in the assumption that the chaff environment is unfavourable for weed seed survival. The chaff row environment effect on weed seed survival was examined in field studies, while chaff response studies determined the influence of increasing amounts of chaff on weed seedling emergence. The objectives of these studies were to determine 1) the influence of chaff lines on the summer-autumn seed survival of selected weed species; and 2) the influence of chaff type and amount on rigid ryegrass seedling emergence. There was frequently no difference (P>0.05) in survival of seed of four weed species (rigid ryegrass, wild oat, annual sowthistle and turnip weed) when these seed were placed beneath or beside chaff lines. There was one instance where wild oat seed survival was increased (P<0.05) when seed were placed beneath compared to beside a chaff line. The pot studies determined that increasing amounts of chaff consistently resulted in decreasing numbers of rigid ryegrass seedlings emerging through chaff material. The suppression of emergence broadly followed a linear relationship where there was approximately a 2.0% reduction in emergence with every 1.0 t ha-1 increase in chaff material. This relationship was consistent across wheat, barley, canola and lupin chaff types, indicating that the physical presence of the chaff was more important than chaff type. These studies indicated that chaff lines may not affect the over summer-autumn survival of the contained weed seeds but the subsequent emergence of weed seedlings will be restricted by high amounts of chaff (>40 t ha-1).

Seed Survival and Seasonal Emergence of Seedlings of Some Ruderal Plants

1984 ◽  
Vol 21 (2) ◽  
pp. 617 ◽  
Author(s):  
H. A. Roberts ◽  
J. E. Boddrell
Keyword(s):  
Seed Survival

scholarly journals Species functional traits and abundance as drivers of multiplex ecological networks: first empirical quantification of inter-layer edge weights

2020 ◽  
Vol 287 (1939) ◽  
pp. 20202127
Author(s):  
S. Hervías-Parejo ◽  
C. Tur ◽  
R. Heleno ◽  
M. Nogales ◽  
S. Timóteo ◽  
...  
Keyword(s):  
Species Traits ◽  
Abundant Species ◽  
Modular Organization ◽  
Vertebrate Species ◽  
Multilayer Network ◽  
Functional Roles ◽  
Different Types ◽  
Seed Dispersers ◽  
Natural Communities

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.

scholarly journals Gibbon and Elephant as Seed Dispersers

2015 ◽  
Vol 96 (4) ◽  
pp. 644-646
Author(s):  
Kim R. McConkey ◽  
Warren Y. Brockelman ◽  
Chanpen Saralamba ◽  
Anuttara Nathalang
Keyword(s):  
Seed Dispersers

scholarly journals Seed Dispersers, Seed Predators, and Browsers Act Synergistically as Biotic Filters in a Mosaic Landscape

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107385 ◽  
Author(s):  
Regino Zamora ◽  
Luis Matías
Keyword(s):  
Mosaic Landscape ◽  
Seed Predators ◽  
Seed Dispersers

Direct and indirect effects of masting on rodent populations and tree seed survival

Oikos ◽  
2002 ◽  
Vol 96 (3) ◽  
pp. 402-410 ◽  
Author(s):  
Jaclyn L. Schnurr ◽  
Richard S. Ostfeld ◽  
Charles D. Canham
Keyword(s):  
Indirect Effects ◽  
Direct And Indirect Effects ◽  
Seed Survival ◽  
Rodent Populations ◽  
Tree Seed

Annual ryegrass (Lolium rigidum) seed survival and digestibility in cattle and sheep

2002 ◽  
Vol 42 (2) ◽  
pp. 111 ◽  
Author(s):  
R. Stanton ◽  
J. Piltz ◽  
J. Pratley ◽  
A. Kaiser ◽  
D. Hudson ◽  
...  
Keyword(s):  
Dry Matter ◽  
Control Diet ◽  
Basal Diet ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Seed Survival ◽  
Dry Matter Digestibility ◽  
Cattle And Sheep

A trial was conducted to investigate the survival and digestibility of annual ryegrass (ARG) seed (Lolium rigidum L.) eaten by sheep and cattle. Sheep (n= 8) and cattle (n = 8) were fed a basal diet containing 1:1 lucerne chaff:oaten chaff with (ARG) or without (control) the inclusion of 20% total dry matter of annual ryegrass seed in a changeover design. Intake was restricted to 17 g/kg liveweight. Digestibility of the control diet was lower (P<0.01) for sheep than cattle. Annual ryegrass seed was present (P<0.01) in the faeces of both sheep and cattle within 24 h of first ingestion. Some 10.8 and 32.8% of seed ingested was excreted by sheep and cattle respectively, with 3.9% (sheep) and 11.9% (cattle) remaining germinable. Annual ryegrass seed continued to be excreted by both sheep and cattle up to 5 days after removal from the diet. Dry matter digestibility of the annual ryegrass diet was 53% in cattle.

scholarly journals Linking seed fate to natural dispersal patterns: factors affecting predation and scatter-hoarding of Virola calophylla seeds in Peru

2005 ◽  
Vol 21 (3) ◽  
pp. 243-253 ◽  
Author(s):  
Sabrina E. Russo
Keyword(s):  
Spider Monkeys ◽  
Seed Fate ◽  
Deposition Pattern ◽  
Scatter Hoarding ◽  
Seed Survival ◽  
Deposition Patterns ◽  
Neotropical Tree ◽  
Ateles Paniscus ◽  
Sleeping Sites ◽  
Seed Deposition

Natural seed deposition patterns and their effects on post-dispersal seed fate are critical in tropical tree recruitment. Previous research showed that the key dispersal agent of the neotropical tree, Virola calophylla, is the spider monkey (Ateles paniscus). Spider monkeys generate a heterogeneous seed deposition pattern because they scatter-disperse seeds diurnally, whereas they clump-disperse seeds at their sleeping sites. The recruitment consequences of this pattern were investigated using manipulative experiments and observations. Scatter-hoarding by spiny rats (Proechimys spp.) caused little rearrangement of the initial seed deposition pattern because they moved seeds only short distances. Seed survival to the seedling stage depended negatively on conspecific seed density and positively on the distance from the nearest adult V. calophylla female. These effects were likely mediated by two important seed predators, spiny rats and beetles (Scolytidae). Furthermore, spider monkeys' seed deposition patterns influenced seed survival. Scatter-dispersed and experimentally dispersed seeds had the highest survival. Conversely, clump-dispersed seeds at sleeping sites, which are far from V. calophylla females, and non-dispersed seeds had equally low survival, suggesting that conspecific density- and distance-dependence acted independently and did not explain all variation in seed survival. Instead, other characteristics of the seed deposition pattern, such as the multi-specific assemblage of seeds at sleeping sites, also affected post-dispersal seed fates.Resumen: La conexión entre el patrón natural de dispersión de semillas con el destino después de la dispersión es clave para el reclutamiento de árboles tropicales. Mediante experimentos y observaciones se investigó esta conexión utilizando el árbol neotropical Virola calophylla (Myristicaceae). Ateles paniscus (maquisapa), el principal dispersor de sus semillas, genera un patrón de deposición heterogéneo. Durante el día las semillas son depositadas de manera esparcida mientras que en los dormitorios las semillas son depositadas de manera agregada. En este estudio se encontró que los roedores espinosos (Proechimys spp.) almacenaron semillas individuales debajo de la hojarasca, sin embargo estos no alteraron el patrón de dispersión ya que las semillas fueron transportadas distancias cortas y la tasa de predación fue alta. Se encontró que la tasa de sobrevivencia hasta la etapa de plántula tuve una relación negativa con la densidad de las semillas y una relación positiva con la distancia al árbol hembra de V. calophylla mas cercano. Estos efectos sucedieron por medio de roedores espinosos y coleópteros (Scolytidae), predadores importantes de las semillas de V. callophylla. Adicionalemente, el patrón de deposición de los maquisapas influenció la sobrevivencia de las semillas. Tanto las semillas dispersadas por los maquisapas como las dispersadas experimentalmente tuvieron la tasa de sobrevivencia más alta. Por el contrario, tanto las semillas depositadas en los dormitorios, usualmente lejos de hembras de V. calophylla, como las semillas que cayeron debajo del árbol hembra tuvieron bajos niveles de sobrevivencia. Estos reultados sugieren que tanto la densidad como la distancia tuvieron efectos independientes y no explicaron toda la variación observada en la sobrevivencia de semillas. Por el contrario, otras características de la deposición de semillas tales como la riqueza de especies de la comunidad de semillas en los dormitorios también afectaron el destino de las semillas después de dispersadas.

Hares (Lepusspp.) as seed dispersers ofRetama raetam(Fabaceae) in a sandy landscape

1997 ◽  
Vol 37 (2) ◽  
pp. 343-354 ◽  
Author(s):  
Ido Izhaki ◽  
Gidi Ne'eman
Keyword(s):  
Seed Dispersers

Diplochory: are two seed dispersers better than one?

2004 ◽  
Vol 19 (3) ◽  
pp. 155-161 ◽  
Author(s):  
Stephen B. Vander Wall ◽  
William S. Longland
Keyword(s):  
Seed Dispersers ◽  
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