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 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.

The effect of gut processing on the quality of mistletoe seed dispersal

2007 ◽  
Vol 23 (3) ◽  
pp. 377-380 ◽  
Author(s):  
Lizanne Roxburgh
Keyword(s):  
Seed Dispersal ◽  
Frugivorous Birds ◽  
The Future ◽  
Future Reproduction ◽  
Number Of Visits ◽  
Fruiting Plant ◽  
Number Of Seeds ◽  
Disperser Effectiveness

Disperser effectiveness is the contribution that a disperser makes to the future reproduction of a plant (Schupp 1993), and it has two components: quality and quantity of dispersal. Quantity of dispersal is a function of the number of visits that a disperser makes to a fruiting plant and the number of seeds that are dispersed during each visit. Quality of dispersal is a function of the treatment that a seed receives from its disperser and the site that the seed is finally deposited in. The quality of seed dispersal of the mistletoe Phragmanthera dschallensis (Engl.) M.G. Gilbert (Loranthaceae) by frugivorous birds was examined in this study.

Frugivores and fruit removal ofAntiaris toxicaria(Moraceae) at Bia Biosphere Reserve, Ghana

2009 ◽  
Vol 25 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Bright Obeng Kankam ◽  
William Oduro
Keyword(s):  
Seed Dispersal ◽  
Tropical Forests ◽  
Seedling Survival ◽  
Biosphere Reserve ◽  
Empirical Measure ◽  
Parent Plant ◽  
Seed Fate ◽  
Fruit Removal ◽  
Adult Trees

In tropical forests, most individual fruit-bearing trees depend on frugivores for seed dispersal (Howe & Smallwood 1982, Wilson 1992). Seed dispersal enhances germination potential, provides an opportunity for seeds to escape predation under the parent plants, and reduces seedling numbers under parent trees (Şekercioğluet al. 2004). The way frugivores handle seeds and process them may influence the seed fate of many plants (Janzen 1971). The quantity of seeds dispersed and the quality of dispersal provided by frugivores impact plant fitness (Herrera & Jordano 1981). Schupp (1993) defined the effectiveness of seed dispersal by frugivores as an empirical measure of quantity of seeds dispersed and quality of dispersal from the parent plant to a suitable microsite. Seed dispersal by frugivores increases the chances for seedling survival away from the vicinity of the parent plant because in tropical forests seed predation is concentrated under adult trees that prevent seedlings from establishing near parent trees (Howe & Miriti 2004).

Dispersal ofAcaciaseeds by ungulates and ostriches in an African savanna

1996 ◽  
Vol 12 (3) ◽  
pp. 345-356 ◽  
Author(s):  
Maxine F. Miller
Keyword(s):  
South Africa ◽  
Seed Dispersal ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Tree Crown ◽  
African Savanna ◽  
Large Herbivores ◽  
Mammalian Herbivores ◽  
Open Environments ◽  
Presence And Absence

ABSTRACTThe dispersal of AfricanAcaciaseeds in the presence and absence of large mammalian herbivores and ostriches was assessed in a savanna ecosystem in South Africa. In the absence of large herbivores,A. tortilisandA. niloticapods were mainly dispersed in the shade, directly beneath the tree crown and seeds remained in pods for over 18 months. In the presence of large herbivores,A. tortilis, A. niloticaandA. karrooseeds were freed from pods and were dispersed into open, non-shaded habitats. Impala dispersed mostA. tortilisseeds (18,900 ha−1), giraffe mostA. niloticaseeds (1060 ha−1) and giraffe and kudu mostA. karrooseeds (452 and 448 ha−1, respectively). Seedling survival in dung in open environments may exceed that of seedlings in soil shaded beneath the tree crown. It appears that seed dispersal by large herbivores may be advantageous to future seedling recruitment.

Automatic approaches for seismic to well tying

2014 ◽  
Vol 2 (2) ◽  
pp. SD9-SD17 ◽  
Author(s):  
Roberto H. Herrera ◽  
Sergey Fomel ◽  
Mirko van der Baan
Keyword(s):  
Dynamic Time Warping ◽  
Local Similarity ◽  
Well Log ◽  
Time Warping ◽  
Similarity Metric ◽  
Entire Process ◽  
Manual Method ◽  
Well Location ◽  
Dynamic Time

Tying the synthetic trace to the actual seismic trace at the well location is a labor-intensive task that relies on the interpreter’s experience and the similarity metric used. The traditional seismic to well tie suffers from subjectivity by visually matching major events and using global crosscorrelation to measure the quality of that tying. We compared two automatic techniques that will decrease the subjectivity in the entire process. First, we evaluated the dynamic time warping method, and then, we used the local similarity attribute based on regularized shaping filters. These two methods produced a guided stretching and squeezing process to find the best match between the two signals. We explored the proposed methods using real well log examples and compared to the manual method, showing promising results with both semiautomatic approaches.

scholarly journals Mutu Fisik Dan Teknik Pematahan Dormansi Benih Kayu Kuku (Pericopsis mooniana (Thw.) Thw.)

2020 ◽  
Vol 11 (3) ◽  
pp. 199-205
Author(s):  
Arum Sekar Wulandari ◽  
Afrida Rizka Farzana
Keyword(s):  
Moisture Content ◽  
Cold Water ◽  
Dormancy Breaking ◽  
Seed Moisture Content ◽  
Physical Quality ◽  
Seed Moisture ◽  
Breaking Seed Dormancy ◽  
Short Time ◽  
Number Of Seeds

The presence of Pericopsis mooniana (Thw.) Thw. in nature is endangered. Meanwhile, Pericopsis mooniana plants have its obstacles in generative propagation because the seeds have mechanical dormancy. Studies carried out to: (1) observe the morphology of pods, seeds and sprouts of Pericopsis mooniana; (2) determine the physical quality of Pericopsis mooniana seeds, and (3) analyze the proper dormancy breaking treatment for Pericopsis mooniana seeds. Research is conducted in laboratories and in greenhouses. The physical quality of the seeds measured was the weight of 1,000 seeds and the moisture content. The treatment for breaking the dormancy of the Pericopsis mooniana seeds were control, scarification of the seeds using nail clippers and soaking in hot to cold water for 48 hours. Morphologically, the fruit of Pericopsis mooniana is pod-shaped, with orange seeds, oval-shaped and curved edges. Pericopsis mooniana sprouts include in the epigeal type. In 1 kg of weight there are ± 4,000 Pericopsis mooniana seeds, with the post harvest seed moisture content amounting to 7.62%. The dormancy breaking treatment of Pericopsis mooniana seeds increased seeds germination by 60% compared to controls. The scarification of Pericopsis mooniana seeds using nail clippers for breaking mechanical dormancy is the best treatment because it can increase the number of seeds germinating in a short time and simultaneously. Key words: breaking seed dormancy, morphology, Pericopsis mooniana, physical quality, seed scarificatio

scholarly journals Anachronic Fruit Traits and Natural History Suggest Extinct Megafauna Herbivores as the Dispersers of an Endangered Tree

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1492
Author(s):  
Diego Muñoz-Concha ◽  
Karla Muñoz ◽  
Andrea P. Loayza
Keyword(s):  
Seed Dispersal ◽  
Management Practices ◽  
Seedling Survival ◽  
Fruit Traits ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Dispersal Syndrome ◽  
Fruit Processing ◽  
Feeding Trials ◽  
Low Efficiency

Megafaunal seed dispersal syndrome refers to a group of traits attributed to the evolution of plants in the presence of large mammals. Present-day plants that bear these traits in areas where megafauna are absent are presumed to represent anachronic dispersal systems. Gomortega keule is an endangered tree species from a monotypic family (Gomortegaceae), endemic to Chile. Its fruit traits suggest adaptation to seed dispersal by large vertebrates; however, none are present today along its area of distribution. Here, we conducted a detailed revision on the fruit morphology of G. keule to examine whether its fruit traits fit a megafaunal dispersal syndrome. Additionally, we examined the fruit processing behavior of large domestic and captive wild animals fed with G. keule fruits, and its effect on germination. G. keule fruits had traits consistent with those of a Type 1 megafaunal fruit. Compared to intact, whole stones, seed germination probabilities decreased when fruits were handled by animals, suggesting that the seed was damaged during mastication and/or ingestion. Moreover, results from our feeding trials with elephants may also imply low efficiency of extinct gomphotheres as seed dispersers of this species. Our results also suggest that although domestic animals may disperse G. keule, it is unlikely that at present they can substitute the services of its original dispersers. Further investigation on seedling survival, local livestock management and forest management practices may help reinstate sexual regeneration in G. keule. Finally, integrating observations on fruit ecology and local people’s knowledge with experimental data enriches our species-centered approach and may help to address regeneration problems in other endangered plants.

Wind-mediated seed dispersal of invasive forage grasses from agricultural grasslands in Hokkaido, Japan

2019 ◽  
Vol 12 (02) ◽  
pp. 133-141
Author(s):  
Chika Egawa ◽  
Atsushi Shoji ◽  
Hiroyuki Shibaike
Keyword(s):  
Seed Dispersal ◽  
Poa Pratensis ◽  
Plant Cover ◽  
Kentucky Bluegrass ◽  
Dispersal Distance ◽  
Phleum Pratense ◽  
Grass Species ◽  
Forage Grass ◽  
Forage Grasses ◽  
Number Of Seeds

AbstractAlthough introduced pasture grasses are essential for forage production in current livestock farming, some species cause serious impacts on native biodiversity when naturalized. Information on the seed dispersal of invasive forage grasses from cultivated settings to surrounding environments can inform management efforts to prevent their naturalization. In this case study, we quantified the wind-mediated seed dispersal distance and amount of dispersed seed of invasive forage grasses from agricultural grasslands in Hokkaido, northern Japan. In total, 200 funnel seed traps were installed around three regularly mown grasslands and one unmown grassland where various forage grass species were grown in mixture. Seeds of each species dispersed outside the grasslands were captured from May to October 2017. Based on the trapped distances of seeds, the 99th percentile dispersal distance from the grasslands was estimated for six species, including timothy (Phleum pratense L.), orchardgrass (Dactylis glomerata L.), and Kentucky bluegrass (Poa pratensis L.). For two dominant species, P. pratense and D. glomerata, the numbers of seeds dispersed outside the field under mown and unmown conditions were determined under various plant cover situations. The estimated dispersal distances ranged from 2.3 m (P. pratense) to 31.5 m (P. pratensis), suggesting that areas within approximately 32 m of the grasslands are exposed to the invasion risk of some forage grass species. For both P. pratense and D. glomerata, the number of seeds dispersed outside the unmown grassland exceeded 100 seeds m−2 under high plant cover situations, while the number of seeds dispersed from the mown grasslands at the same plant cover level was less than one-third of that number. The results suggest that local land managers focus their efforts on frequent mowing of grasslands and monitoring of the areas within approximately 32 m of the grasslands to substantially reduce the naturalization of invasive forage grasses.

ITC Limited: Decoding Business Segment Betas

2019 ◽  
Vol 23 (02) ◽  
pp. 203-235
Author(s):  
Shalini Talwar ◽  
Anmol Garg
Keyword(s):  
Average Cost ◽  
Cost Of Capital ◽  
Investment Decisions ◽  
Weighted Average ◽  
Extensive Discussion ◽  
Entire Process ◽  
The Third ◽  
The Future

OCV was seeking to improve its processes and enhance the skills of its analysts so as to provide valuable solutions for their clients in terms of the issues related to the profitability and risk of their existing business portfolios as well as the proposed new projects. A team was formed to evaluate if breaking down the weighted average cost of capital (WACC) to the divisional level could improve the quality of investment decisions by multi-division firms. ITC was chosen to analyse the entire process of breaking down WACC to the divisional level. The team had three distinct tasks to undertake. The first was the calculation of the divisional WACC for different business segments of ITC, the second was an extensive discussion on the issues that could arise in the complex computations, and the third was to take a final call on whether the breaking down of WACC to the divisional level would really add value to the future investment decisions.

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