Input of wind–dispersed seeds into light–gaps and forest sites in a Neotropical forest

1988 ◽  
Vol 4 (3) ◽  
pp. 239-252 ◽  
Author(s):  
Carol K. Augspurger ◽  
Susan E. Franson
Keyword(s):  
Seed Rain ◽  
Community Level ◽  
Barro Colorado Island ◽  
High Fecundity ◽  
Neotropical Forest ◽  
Study Plot ◽  
Forest Sites ◽  
Light Gaps ◽  
Growth Of Seedlings ◽  
Light Gap

ABSTRACTA total of 52,467 wind-dispersed seeds from 14 tree and 32 liana species fell into 1720 seed traps in 43 paired light-gap and adjacent forest sites on Barro Colorado Island, Panama. Summed at the community level, many more wind-dispersed seeds were collected from light-gaps (61%) than from forest sites (39%). They accumulated from March through May, 1984 to a density of 328 m-2 in gaps and 207 m-2 in forest sites. In contrast, only 33% of the total of 2782 non-wind-dispersed seeds were collected in gaps. Due to the extreme heterogeneity of the seed rain, these differences between gap and forest sites were not statistically significant at the community-level. Gap sites received more wind-dispersed seeds than adjacent forest sites in only 20 of 43 locations and in 13 of 20 species, especially those with individuals of high fecundity near gap sites. Of the estimated 105 million wind-dispersed seeds contributing to the seed rain of the 50 ha study plot, only 4.1% were dispersed to the rare gap sites that enhance the establishment and growth of seedlings for many of these species.

Seed-dispersal and seedling recruitment patterns by the last Neotropical megafaunal element in Amazonia, the tapir

2000 ◽  
Vol 16 (3) ◽  
pp. 369-385 ◽  
Author(s):  
José M. V. Fragoso ◽  
Jean M. Huffman
Keyword(s):  
Seedling Recruitment ◽  
Germination Rate ◽  
Seed Viability ◽  
Seed Rain ◽  
Dry Land ◽  
Forest Sites ◽  
Seed Dispersion ◽  
Tapirus Terrestris ◽  
Spatio Temporal ◽  
Seed Shadows

Tapirs (Tapiridae) are the last representatives of the Pleistocene megafauna of South and Central America. How they affect the ecology of plants was examined by studying the diversity, abundance, and condition of seeds defecated by the lowland tapir (Tapirus terrestris) in Amazonian Brazil. Additionally, the spatio-temporal pattern of the seed-rain and seed-shadows generated by tapirs was recorded. Three hundred and fifty-six tapir faeces were examined. Eleven per cent were found in water (n = 41), while 88% were located on dry land (n = 315). Of those found on dry land, 84% were located at sites that flood seasonally, while 14% of the total were encountered at forest sites that do not flood. In 127 faeces checked in the laboratory over 12 906 seeds of at least 39 species were found. Seed viability ranged from 65% for Maximiliana maripa to 98% for Enterolobium schomburgkii. Of nine seed species planted in the laboratory, seven germinated within 4 wk, with one species achieving an 89% germination rate. For many species recruitment to the seedling stage was also high under natural conditions, with 13 plant species occurring as seedlings in older faeces. Tapir generated seed-rain occurred throughout the year, with seeds defecated in all months. Two temporal patterns in species seed rain occurred: (1) contiguous monthly occurrence with peaks in abundance, and (2) discontinuous occurrence (time clumped) with small (a few months) to large (many months to more than a year) temporal gaps. The highest diversity of seeds appeared in April, at the end of the dry season. As the last of the Pleistocene megafauna of the region, tapirs may have particular importance as dispersers of large seeds and generators of unique seed dispersion patterns.

Forest Dynamics with Canopy Gap Expansion and Stochastic Ising Model

Fractals ◽  
1998 ◽  
Vol 06 (01) ◽  
pp. 81-86 ◽  
Author(s):  
Makoto Katori ◽  
Shinya Kizaki ◽  
Youichi Terui ◽  
Takuya Kubo
Keyword(s):  
Ising Model ◽  
Forest Dynamics ◽  
Ecological Study ◽  
Gibbs State ◽  
Canopy Gap ◽  
Barro Colorado Island ◽  
Gap Size ◽  
Stochastic Ising Model ◽  
Neotropical Forest ◽  
Gap Creation

Importance of the influence of neighboring canopy gaps upon new gap creation has been clarified by the ecological study of a neotropical forest on Barro Colorado Island (BCI), Panama. A stochastic lattice model for the forest dynamics with interacting canopy gap expansion was introduced by Kubo et al. We give a theorem showing a condition that this model can be regarded as a stochastic Ising model, and that its stationary state is exactly given by a Gibbs state. Using this theorem, we obtain a Gibbs state which remarkably well approximates the real gap-size distribution in BCI.

scholarly journals Variation in potential for isoprene emissions among Neotropical forest sites

2004 ◽  
Vol 10 (5) ◽  
pp. 630-650 ◽  
Author(s):  
Peter Harley ◽  
Pérola Vasconcellos ◽  
Lee Vierling ◽  
Carlos Cleomir de S. Pinheiro ◽  
James Greenberg ◽  
...  
Keyword(s):  
Neotropical Forest ◽  
Forest Sites

scholarly journals Sleeping-tree fidelity of the spider monkey shapes community-level seed-rain patterns in continuous and fragmented rain forests

2015 ◽  
Vol 31 (4) ◽  
pp. 305-313 ◽  
Author(s):  
Arturo González-Zamora ◽  
Víctor Arroyo-Rodríguez ◽  
Federico Escobar ◽  
Ken Oyama ◽  
Filippo Aureli ◽  
...  
Keyword(s):  
Forest Type ◽  
Species Turnover ◽  
Seed Rain ◽  
Spider Monkey ◽  
Community Level ◽  
Food Density ◽  
Frequency Of Use ◽  
Repeated Use ◽  
Fragmented Forests ◽  
Study Sites

Abstract:Repeated use of sleeping trees (STs) by frugivores promotes the deposition and aggregation of copious amounts of seed, thus having key implications for seed dispersal and forest regeneration. Seed-rain patterns produced by this behaviour likely depend on the frequency of use of these sites, yet this hypothesis has been poorly tested. We evaluated community-level seed-rain patterns produced by the spider monkey (Ateles geoffroyi) over 13 mo in latrines located beneath 60 STs in the Lacandona rain forest, Mexico. Because this primate is increasingly ‘forced’ to inhabit fragmented landscapes, we tested whether sleeping-tree fidelity (STF) differed among sites and between continuous and fragmented forests. We also tested whether seed-rain patterns were associated with STF within each site and forest type. STF was highly variable among STs (average = 7 mo, range = 1–12 mo), but did not differ among study sites or forest types. STF was positively associated with seed abundance, species diversity and species turnover. Nevertheless, STF tended to be negatively related to seed community evenness. These results are likely due to the most frequently used STs being in areas with greater food density. Our results demonstrate that site fidelity shapes community-level seed-rain patterns and thus has key ecological implications.

The canopy gap regime in a secondary Neotropical forest in Panama

1995 ◽  
Vol 11 (3) ◽  
pp. 391-402 ◽  
Author(s):  
Joseph B. Yavitt ◽  
John J. Battles ◽  
Gerald E. Lang ◽  
Dennis H. Knight
Keyword(s):  
Secondary Forest ◽  
Environmental Gradients ◽  
Canopy Gaps ◽  
Barro Colorado Island ◽  
First Year ◽  
Gap Formation ◽  
Neotropical Forest ◽  
Mean Size ◽  
Small Plot ◽  
The Mean

ABSTRACTWe mapped the occurrence of canopy gaps periodically between 1978 and 1990 in a 1.5 ha study plot within a 70-year-old (in 1978) Neotropical forest on Barro Colorado Island (BCI), Republic of Panama. The total area of the forest under canopy gaps in the plot averaged 4.3% (3.1% to 5.7%, 95% CI). There was high year-to-year variability in the rate of new gap formation. On the basis of repeated observations for four yearly intervals, the annual rate of new gap formation ranged from 0.45% y−1 to 6.5% y−1. Most gaps were small. The mean size of individual gaps originally was 79 m2 (range: 8-604 m2). However, large gaps (≥150 m2) occurred more frequently than expected for a secondary forest on BCI. Gaps closed rapidly the first year after formation but the rate of closure slowed thereafter. Despite the absence of any obvious environmental gradients, gaps were spatially clustered. Even in this relatively small plot, there seemed to be distinct gap-prone and gap-free areas.

scholarly journals Late-season surveys to document seed rain potential of Palmer amaranth (Amaranthus palmeri) and waterhemp (Amaranthus tuberculatus) in Texas cotton

2019 ◽  
Author(s):  
Kaisa M. Werner ◽  
Debalin Sarangi ◽  
Scott A. Nolte ◽  
Peter A. Dotray ◽  
Muthukumar V. Bagavathiannan
Keyword(s):  
Seed Rain ◽  
Palmer Amaranth ◽  
High Plains ◽  
Amaranthus Palmeri ◽  
Weed Species ◽  
Species Persistence ◽  
High Fecundity ◽  
Late Season ◽  
Central Texas ◽  
Cotton Fields

AbstractDespite the best weed control efforts, weed escapes are often present in large production fields prior to harvest, contributing to seed rain and species persistence. Late-season surveys were conducted in cotton (Gossypium hirsutum L.) fields in Texas in 2016 and 2017 to identify common weed species present as escapes and estimate seed rain potential of Palmer amaranth (Amaranthus palmeri S. Watson) and waterhemp [A. tuberculatus (Moq.) J.D. Sauer], two troublesome weed species with high fecundity. A total of 400 cotton fields across four major cotton-producing regions in Texas [High Plains (HP), Gulf Coast (GC), Central Texas, and Blacklands] were surveyed. Results have revealed that A. palmeri, Texas millet [Urochloa texana (Buckley) R. Webster], A. tuberculatus, ragweed parthenium (Parthenium hysterophorus L.), and barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] were the top five weed escapes present in cotton fields. Amaranthus palmeri was the most prevalent weed in the HP and Lower GC regions, whereas A. tuberculatus escapes were predominantly observed in the Upper GC and Blacklands regions. On average, 9.4% of an individual field was infested with A. palmeri escapes in the Lower GC region; however, it ranged between 5.1 and 8.1% in the HP region. Average A. palmeri density ranged from 405 (Central Texas) to 3,543 plants ha−1 (Lower GC). The greatest seed rain potential by A. palmeri escapes was observed in the upper HP region (13.9 million seeds ha−1), whereas the seed rain potential of A. tuberculatus escapes was the greatest in the Blacklands (12.9 million seeds ha−1) and the upper GC regions (9.8 million seeds ha−1). Results indicated that seed rain from late-season A. palmeri and A. tuberculatus escapes are significant in Texas cotton, and effective management of these escapes is imperative for minimizing seedbank inputs and impacting species persistence.

scholarly journals Environmental gradients and the evolution of successional habitat specialization: a test case with 14 Neotropical forest sites

2015 ◽  
Vol 103 (5) ◽  
pp. 1276-1290 ◽  
Author(s):  
Susan G. Letcher ◽  
Jesse R. Lasky ◽  
Robin L. Chazdon ◽  
Natalia Norden ◽  
S. Joseph Wright ◽  
...  
Keyword(s):  
Environmental Gradients ◽  
Habitat Specialization ◽  
Test Case ◽  
Neotropical Forest ◽  
Forest Sites

scholarly journals Applying and refining DNA analysis to determine the identity of plant material extracted from the digestive tracts of katydids

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6808 ◽  
Author(s):  
Laurel B. Symes ◽  
Nicole L. Wershoven ◽  
Lars-Olaf Hoeger ◽  
Jessica S. Ralston ◽  
Sharon J. Martinson ◽  
...  
Keyword(s):  
Plant Material ◽  
Dna Analysis ◽  
Feeding Habits ◽  
Time Of Day ◽  
Barro Colorado Island ◽  
Gut Contents ◽  
Neotropical Forest ◽  
Amplification Success ◽  
Significant Difference ◽  
Primer Sets

Background Feeding habits are central to animal ecology, but it is often difficult to characterize the diet of organisms that are arboreal, nocturnal, rare, or highly mobile. Genetic analysis of gut contents is a promising approach for expanding our understanding of animal feeding habits. Here, we adapt a laboratory protocol for extracting and sequencing plant material from gut contents and apply it to Neotropical forest katydids (Orthoptera: Tettigoniidae) on Barro Colorado Island (BCI) in Panama. Methods Our approach uses three chloroplast primer sets that were previously developed to identify vegetation on BCI. We describe the utility and success rate of each primer set. We then test whether there is a significant difference in the amplification and sequencing success of gut contents based on the size or sex of the katydid, the time of day that it was caught, and the color of the extracted gut contents. Results We find that there is a significant difference in sequencing success as a function of gut color. When extracts were yellow, green, or colorless the likelihood of successfully amplifying DNA ranged from ~30–60%. When gut extracts were red, orange, or brown, amplification success was exceptionally low (0–8%). Amplification success was also higher for smaller katydids and tended to be more successful in katydids that were captured earlier in the night. Strength of the amplified product was indicative of the likelihood of sequencing success, with strong bands having a high likelihood of success. By anticipating which samples are most likely to succeed, we provide information useful for estimating the number of katydids that need to be collected and minimizing the costs of purifying, amplifying, and sequencing samples that are unlikely to succeed. This approach makes it possible to understand the herbivory patterns of these trophically important katydids and can be applied more broadly to understand the diet of other tropical herbivores.

Allometry, adult stature and regeneration requirement of 65 tree species on Barro Colorado Island, Panama

2006 ◽  
Vol 22 (2) ◽  
pp. 123-136 ◽  
Author(s):  
Stephanie Bohlman ◽  
Sean O'Brien
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Stand Structure ◽  
Community Level ◽  
Barro Colorado Island ◽  
Diameter Growth ◽  
Tree Allometry ◽  
Level Analysis ◽  
Canopy Species ◽  
Adult Stature

This study provides a community-level analysis of how regeneration requirement and adult stature are related to tree allometry (diameter, height and crown size) throughout post-seedling ontogeny on Barro Colorado Island, Panama. Comparing 65 species, gap species are taller, have higher diameter growth rates and occupy more low-canopy sites (≤10 m canopy height) than shade species at small diameters (≤10 cm dbh). For trees >10 cm dbh, diameter-height relationships and growth rates no longer differ between gap and shade species, but shade species have larger, particularly deeper, crowns than gap species. Species with tall adult stature have more slender stems with larger crowns compared with treelet and mid-canopy species starting at 5 cm dbh. From 10 to 40 cm dbh, diameter growth rate is also significantly greater for tall species. The consistent allometric differences between functional groups on a community level will, in part, determine vertical and horizontal stand structure.

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