Controlled Seed Deposition for Generating Bi-directional Rows

2011 ◽  
Author(s):  
Peter Schulze Lammers ◽  
Oliver Schmittmann ◽  
Hing Kam
Keyword(s):  
Seed Deposition

scholarly journals Fire suppression and seed dispersal play critical roles in the establishment of tropical forest tree species in southeastern Africa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomohiro Fujita
Keyword(s):  
Seed Dispersal ◽  
Tree Species ◽  
Seedling Survival ◽  
Fire Suppression ◽  
Forest Tree ◽  
Tree Seedlings ◽  
Seedling Mortality ◽  
Forest Tree Species ◽  
Seed Deposition ◽  
Syzygium Guineense

AbstractThis study examined the mechanisms of facilitation and importance of seed dispersal during establishment of forest tree species in an Afrotropical woodland. Seedling survival of Syzygium guineense ssp. afromontanum was monitored for 2.5 years at four different microsites in savannah woodland in Malawi (southeastern Africa) under Ficus natalensis (a potential nurse plant), Brachystegia floribunda (a woodland tree), Uapaca kirkiana (a woodland tree), and at a treeless site. The number of naturally established forest tree seedlings in the woodland was also counted. Additionally, S. guineense ssp. afromontanum seed deposition was monitored at the four microsites. Insect damage (9% of the total cause of mortality) and trampling by ungulates (1%) had limited impact on seedling survival in this area. Fire (43%) was found to be the most important cause of seedling mortality and fire induced mortality was especially high under U. kirkiana (74%) and at treeless site (51%). The rate was comparatively low under F. natalensis (4%) and B. floribunda (23%), where fire is thought to be inhibited due to the lack of light-demanding C4 grasses. Consequently, seedling survival under F. natalensis and B. floribunda was higher compared with the other two microsites. The seedling survival rate was similar under F. natalensis (57%) and B. floribunda (59%). However, only a few S. guineense ssp. afromontanum seedlings naturally established under B. floribunda (25/285) whereas many seedlings established under F. natalensis (146/285). These findings indicate that the facilitative mechanism of fire suppression is not the only factor affecting establishment. The seed deposition investigation revealed that most of the seeds (85%) were deposited under F. natalensis. As such, these findings suggest that in addition to fire suppression, dispersal limitations also play a role in forest-savannah dynamics in this region, especially at the community level.

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.

Next Generation Electrochemical Deposition TSV Fill

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001523-001535
Author(s):  
Bioh Kim ◽  
Stephen Golovato ◽  
Tyler Barbera ◽  
Keiichi Fujita ◽  
Takashi Tanaka
Keyword(s):  
Aspect Ratio ◽  
Electrochemical Deposition ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Scale Production ◽  
Next Generation ◽  
Typical Structure ◽  
Die Stacking ◽  
Seed Deposition

The first generation of through silicon via (TSV) designs for interposer and 3D die stacking has concentrated on TSV features with aspect ratio (AR) on the order of ten. Typical via sizes are 10 X 100 um for interposer and 5 X 50 um for 3D applications. Ionized physical vapor deposition (IPVD) has been successful in depositing barrier and seed layers in these AR=10 vias that allow efficient “bottom-up” filling by electrochemical deposition (ECD) using available chemistries. While these applications are currently moving to pilot lines and low scale production, research and development has already begun on the next generation of TSV structures for interposer and die stacking. These may be based on via middle or via last designs. They are expected to increase in aspect ratio for denser TSV arrays while maintaining similar wafer thickness. Structures with AR in the range of 15–20 are being designed and produced. For interposer, a typical structure might be 8 X 120 um and 2 X 40 um for 3D stacks. These structures will challenge all TSV formation processes, including etch, dielectric liner deposition, barrier-seed deposition and TSV fill. This paper will focus on barrier-seed and TSV fill processes. IPVD barrier-seed deposition will be difficult for AR~15–20 and will require much longer deposition times for complete via coverage. Long IPVD times will produce thick overburden and pinch off the opening at the top of vias. Even if successful, IPVD may not be viable economically. More conformal deposition processes, such as atomic layer deposition (ALD), chemical vapor deposition (CVD) and wet processes, like electro-less plating and conformal ECD, may be better alternatives to IPVD. A conformal process only needs to deposit the minimum required seed thickness in the via for successful ECD filling with the overburden being nearly the same thickness. The development of a successful conformal barrier-seed process may even challenge IPVD for AR=10. This paper presents ECD TSV fill results using several conformal barrier-seed processes, demonstrating the feasibility of this approach for structures with AR = 10–20.

Pattern and impact of hornbill seed dispersal at nest trees in a moist evergreen forest in Thailand

2004 ◽  
Vol 20 (5) ◽  
pp. 545-553 ◽  
Author(s):  
Shumpei Kitamura ◽  
Takakazu Yumoto ◽  
Pilai Poonswad ◽  
Naohiko Noma ◽  
Phitaya Chuailua ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Breeding Season ◽  
Seedling Survival ◽  
Evergreen Forest ◽  
Seedling Mortality ◽  
Entire Process ◽  
Nest Sites ◽  
Seed Deposition ◽  
Number Of Seeds

Following the entire process of frugivore seed dispersal, from intake of seeds to seed deposition, is a difficult task. One alternative is to monitor areas of heavy seed rain deposited by animals. We quantified the number of seeds deposited by hornbills and followed the fates of these seedlings for 3 y to evaluate the effectiveness of hornbill seed dispersal at nest trees, on the basis of seedling survival. For 14 mo, fallen fruits and seeds were collected in traps established around four nest trees of each of two hornbill species (Aceros undulatus and Anthracoceros albirostris) and the seedlings were monitored in adjacent quadrats. Seedfall and seedlings of species represented in hornbill diets occurred at significantly higher densities in the traps/quadrats in front of nest cavities than in other traps/quadrats. Fewer seedling species and individuals germinated under nest trees than expected from the composition of the seedfall. Our results suggest that the quality of hornbill seed dispersal might be poor at nest trees due to the highly concentrated seedfall, which results in high seed and seedling mortality. Although seed deposition at nest trees is a useful guide to hornbill diet during the breeding season, it is clearly not of benefit to the plants involved. However, the pattern and consequences of hornbill seed dispersal at nest sites is likely very different from that during the non-breeding season.

scholarly journals Seed Shadows of Northern Pigtailed Macaques within a Degraded Forest Fragment, Thailand

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1184
Author(s):  
Eva Gazagne ◽  
Jean-Luc Pitance ◽  
Tommaso Savini ◽  
Marie-Claude Huynen ◽  
Pascal Poncin ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Seedling Recruitment ◽  
Mechanistic Model ◽  
Cheek Pouch ◽  
Degraded Forest ◽  
Forest Fragment ◽  
Plantation Forests ◽  
Maximum Range ◽  
Seed Deposition ◽  
Seed Shadows

Research Highlights: Frugivores able to disperse large seeds over large distances are indispensable for seedling recruitment, colonization and regeneration of tropical forests. Understanding their effectiveness as seed dispersal agents in degraded habitat is becoming a pressing issue because of escalating anthropogenic disturbance. Although of paramount importance in the matter, animal behaviour’s influence on seed shadows (i.e., seed deposition pattern of a plant population) is difficult to evaluate by direct observations. Background and Objectives: We illustrated a modeling approach of seed shadows incorporating field-collected data on a troop of northern pigtailed macaques (Macaca leonina) inhabiting a degraded forest fragment in Thailand, by implementing a mechanistic model of seed deposition with random components. Materials and Methods: We parameterized the mechanistic model of seed deposition with macaque feeding behavior (i.e., consumed fruit species, seed treatments), gut and cheek pouch retention time, location of feeding and sleeping sites, monthly photoperiod and movement patterns based on monthly native fruit availability using Hidden Markov models (HMM). Results: We found that northern pigtailed macaques dispersed at least 5.5% of the seeds into plantation forests, with a majority of medium- to large-seeded species across large distances (mean > 500 m, maximum range of 2300 m), promoting genetic mixing and colonization of plantation forests. Additionally, the macaques produced complementary seed shadows, with a sparse distribution of seeds spat out locally (mean >50 m, maximum range of 870 m) that probably ensures seedling recruitment of the immediate plant populations. Conclusions: Macaques’ large dispersal distance reliability is often underestimated and overlooked; however, their behavioral flexibility places them among the last remaining dispersers of large seeds in disturbed habitats. Our study shows that this taxon is likely to maintain significant seed dispersal services and promote forest regeneration in degraded forest fragments.

scholarly journals Wind-dispersed Seed Deposition Patterns and Seedling Recruitment of Artemisia halodendron in a Moving Sandy Land

2005 ◽  
Vol 96 (1) ◽  
pp. 69-80 ◽  
Author(s):  
FENG-RUI LI ◽  
TAO WANG ◽  
AI-SHENG ZHANG ◽  
LI-YA ZHAO ◽  
LING-FEN KANG ◽  
...  
Keyword(s):  
Seedling Recruitment ◽  
Sandy Land ◽  
Deposition Patterns ◽  
Artemisia Halodendron ◽  
Seed Deposition

Effect of the Sowing Speed on the Distribution Regularity of Maize Seeds

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Wesley Nadin ◽  
Pedro Silvério Xavier Pereira ◽  
Onassis Henrique Simon Rondon ◽  
Matheus Farinha Afonso ◽  
Dryelle Sifuentes Pallaoro ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Longitudinal Distribution ◽  
Initial Population ◽  
Precision Index ◽  
Maize Seeds ◽  
Plant Stand ◽  
The Mean ◽  
Seed Deposition ◽  
Displacement Speed ◽  
Deposition Depth

This work aimed to evaluate the influence of the sowing speed on the regularity of longitudinal distribution of maize seeds through a pneumatic metering seeder. The experimentation of 4 sowing speeds (4, 6, 8 and 10 km h-1) was performed in randomized blocks design with four replicates. The parameters evaluated were the mean distance between plants, coefficient of variation of the distance between plants, percentage of acceptable, flawed and double spacings, precision index, plant stand, initial population, mean seed deposition depth, and coefficient of variation of the seed deposition depth. The increase in the operating speed linearly reduced the percentage of acceptable spacings, plant stand, initial population, and mean seed deposition depth. Conversely, it linearly increased the values of mean distance between plants, coefficient of variation of the distance between plants, percentage of double and flawed spacings, precision index, and coefficient of variation of the deposition depth. Therefore, the increase in the displacement speed of the tractor-seeder set reduced the regularity of the longitudinal distribution of the plants, as well as the sowing quality.

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