Reproduction of Besleria princeps in Monteverde Cloud Forests Michelle Murphy Department of Environmental Studies, The University of Oregon _____________________________________________________________________________________ ABSTRACT : The purpose of this study was to show the occurrence of asexual versus sexual reproduction in lower premontane cloud forest, on the Atlantic slope and the Pacific slope of the TilarÃ¡n Mountain range near the Monteverde Biological Station. Eight hundred plants, 400 on the Atl antic slope and 400 on the Pacific side, were examined at their roots for fragmentation and seeding. The elevations of each slope and a comparison of the two slopes were examined using a chi squared two way contingency test. The results showed that asexual reproduction (fragments) is more common in Besleria princeps than sexual reproduction (from seeds). The Atlantic slope and the highest elevations of each slope, showed a higher frequency of fragments to seeds in the windier and wetter conditions. The chi squared results of the Pacific slope elevations were significant, xÂ² = 29.609; df = 3, and a p value <.0001. The Atlantic slope elevations chi squared test had significant results, xÂ² = 21.212, df = 2, and a p value < .0001. The results of the Atlantic slope versus the Pacific slope showed significant chi squared results, xÂ² = 41.439, df = 1, and a p value <.0001. RESUMEN El propÃ³sito de este estudio fue mostrar la existencia de reproducciÃ³n asexual versus la reproducci Ã³n sexual en el bosque nuboso pre montano , en las laderas AtlÃ¡ntica y PacÃfica de la Cordillera de TilarÃ¡n cerca de la EstaciÃ³n biolÃ³gica de Monteverde. Ochocientas plantas, 400 en la ladera AtlÃ¡ntica y 400 en la ladera PacÃfica, fueron examinadas en sus r aÃces para encontrar fragmentaciÃ³n y semillas. Se examinÃ³ las elevaciones para cada pendiente y la comparaciÃ³n de las dos pendientes utilizando una prueba de chi cuadrado de contingencia de dos colas. Los resultados mostraron que la reproducciÃ³n (fragmento s) asexual es mÃ¡s comÃºn en Besleria princeps que la reproducciÃ³n sexual (de semillas). La ladera atlÃ¡ntica y las elevaciones mÃ¡s comunes en Besleria princeps que la reproducciÃ³n sexual (de semillas). La ladera atlÃ¡ntica y las elevaciones mÃ¡s altas de cada pendiente, mostraron una frecuencia mÃ¡s alta de fragmentos que de semillas en las condiciones mÃ¡s ventosas y mÃ¡s hÃºmedas. Los resultados de chi cuadrado de la ladera PacÃfica fueron significativos, xÂ² = 29.609; df = 3, y un valor P <,0001. La prueba de chi cuadrado de la ladera AtlÃ¡ntica tuvo resultados significativos, xÂ² =21. 212, df = 2, y un valor P < .0001. Los resultados de la ladera AtlÃ¡ntica versus la ladera PacÃfica mostraron resultados de chi cuadrado significativos, xÂ² = 41.439, df = 1, y un valor de p de < .0001.
INTRODUCTION Besleria princeps is an herbaceous plant with the characteristic pubescent leaves and stem of its family, as well as the ability to reproduce sexually and asexually. Its flowers are orange and tubular, like those in its gen us. Its characteristics of brightly colored and tubular flowers as well as a low growing stature are contrasting. Generally, colorful and tubular flowers are specialized for pollinator like hummingbirds, but B. princeps have no nectar reward and are close to the ground. Besleria princeps characteristics seem to be misleading considering all these findings. The specific type of asexual reproduction of Besleria princeps is called fragmentation, where parts of the plant roo t into the ground after they have been broken organism produces other organisms more or less similar to itself. The ways in which species reproduce differ, but the two ma in methods are by asexual reproduction are clones of the parent and there is no variation. (Hutchinson Dictionary of Science B. princeps primary form of reproduct ion is fragmentation, then the majority of the study group of plants are clones of one another. Is this reproduction type good for the fitness of the plant? Areas with wet conditions, high amounts of disturbance, and an abundant source of fragments are mos t conducive to fragment reproduction. These are the conditions
found in the misty cloud forest of Monteverde, where a majority of shrub species in Monteverde are capable of reproduction through plant fragments (Bush 2000). Besleria princeps has not been st udied much in the Monteverde Cloud Forest (Masters, 2003, pers. comm.). I studied B. princeps to provide more general information that can be useful for conservationists and biologists in Monteverde. I studied the frequency of fragment plants and seed plan ts at different elevations because wind, sun, moisture, are all factors that vary with altitude change, and may vary the frequency of fragment plants and seed plants. The purpose of this study was to examine if B. princeps reproduces asexually in the fores t of the Monteverde Biological Station. This study compared the number of fragments versus the number of seeds of the Atlantic slope to the Pacific slope, and compared the elevations on each slope to see if there was an altitudinal gradient. MATERIALS AND METHODS: The study was conducted in lower montane life zones, on the Sendero Principal of the Pacific slope and the Atlantic slope of the forest of the Monteverde Biological Station. Besleria princeps were found five to ten meters off the main trails betw een October 29 and November 14, 2003. I examined the roots of the B. princeps for fragment plants (FP) or seed plants (SP). I carefully removed a total of 800 plants from the forest, 400 from the Atlantic slope and 400 from the Pacific slope. One hundred p lants were examined in altitudinal transects at every 50 meters. I measured the elevations using a calibrated altimeter.
I pulled out the plants, digging around the roots, keeping them as intact as possible. The roots of each plant were checked from the bo ttom of their tips to the stem, in search of incomplete roots, and signs of fragmentation. Fragmentation was fairly obvious to see, generally there were brown pieces of half or semi dead fragments that could be traced down to the roots or on the roots. The data were analyzed using chi squared, two way contingency tests. FP versus SP were tested from the elevations on the Pacific and Atlantic slopes. FP versus SP were tested from the elevations on the Pacific slope versus the Atlantic slope. I calculated the individual chi square significance of each cell to compare the values at each elevation, and of each cell result. The elevations I worked at, on the Pacific side, began at 1650 meters and ended at 1850 meters. The elevations I worked at, on the Atlantic s ide, began at 1750 meters and ended at 1850 meters. The number of SP and FP were counted and recorded every 50 meters and 100 plants per transect were examined. The Atlantic slope trails lead to a pasture at about 1700 meters, so I took the counts of 200 p lants from two trails at 1700 meters to get a count of 400 plants on each slope to compare Atlantic versus Pacific SP and FP. RESULTS: The overall chi squared results of the Pacific slope elevations were significant. The results were xÂ² = 29.609; df = 3, and a p value <. 0001. The individual chi squared cell values of elevations 1750m and 1800m showed results with the strongest significance.
At 1750 meters, the expected value for the number of seeds, 29.25, was lower then the observed value, 47. The expected number of fragments, 70.75, was higher than the observed value, 53. At 1800 meters, the expected value for the number of seeds, 29.25, was higher then the observed value, 12. The expected number of fragments, 70.75, was lower then the observed val ue, 88. The Atlantic slope elevations chi squared test, overall, had significant results, xÂ²=21.212, df = 2, and a p value <.0001. The individual chi squared cell values of elevation 1700m showed results with the strongest significance. At 1700 meters, the expected value for the number of seeds, 88, was higher then the observed value, 76. The expected number of fragments, 12, was lower than the observed value, 24. The results of the Atlantic slope versus the Pacific slope showed significant chi squared resu lts. The results were xÂ² = 41.439, df = 1, and a p value <.0001. The Atlantic slope expected value for the number of seeds, 80.5, was higher then the observed value, 44. The expected number of fragments, 319.5, was lower than the observed value, 356. The P acific slope expected value for the number of seeds, 80.5, was higher then the observed value, 117. The expected number of fragments, 319.5, was higher than the observed value, 283.
DISCUSSION: This study showed that fragmentation is the common form of rep roduction of Besleria princeps in the forest of the Monteverde Biological Station. Exposure to the intense northeast trade winds seems to favor regeneration through fragmentation (Bush 2000). The effects of the northeast trade winds can be seen in the comp arison of the Atlantic slope versus the Pacific slope results, where there is a far greater number of FP on the Atlantic slope compared to the Pacific slope. The northeast trade winds keep the Atlantic slope consistently wetter, windier; therefore the Atla ntic slope has favorable conditions for fragmentation. The Pacific slope elevation results had significance at the highest altitude, 1800 meters, where there were a low number of plants by seeds and a high number of fragments. Higher elevations tend to hav e windier conditions, which would explain why the highest altitudinal transect of the Pacific side had the greatest number of fragments and the lowest number of seeds. The Atlantic slope had significant results at the lowest elevation, 1700 meters. The res ults showed a smaller number of fragments and a higher number of seeds versus the two higher elevations. There may be a correlation between this elevation and its placement on the Atlantic slope. The end of this transect was where the forest ended and beca me a pasture. It is possible that the open pasture allows for pollinators and dispersers to reach the plants more easily.
Fragments are prone to rotting and many fall directly below their parent plant, where there are greater amounts of seedling predation, and competition (Heyn 1996). Fragmentation might decrease the fitness of a plant species; since the fitness of a plant is influence by the distance it can disperse its seeds. Besleria princeps is mostly relying on fragmentation to reproduce, and could pos sibly be creating a bottleneck effect where consequence to bottlenecking is genetic deterioration (Masters 2003) and reduced fitness of B. princeps. Hummingbirds are the sug gested pollinators of B. princeps (K.L. Masters, 2003, pers. comm.) but have not been seen pollinating the flowers. The location and stature of B. princeps makes it seem an unlikely candidate for hummingbird pollination. The results in this paper show that B. princeps may not have a consistent pollinator because it reproduces mostly from fragments. Future studies need to be done on B. princeps pollinator(s), to find if it is in fact a hummingbird. Who are the dispersers of B. princeps ? Seed plants have been found of B. princeps , but the pollinators and dispersers are unknown. Further studies would be helpful to increase the general knowledge about B. princeps in the Monteverde Cloud Forests. ACKNOWLEDGEMENTS : I would like to give a spe cial thanks to Allan and Karen Masters, who are visionaries for their work in conservation. Thank you to the Monteverde Biological Station, my
stomping grounds. A special thanks to Carmen, who helped me survive this trip. Thanks to T.A. Matt for all your h elp. Thanks to my parents who are rad for sending me here. LITERATURE CITED : ALDRICH P.R. and HAMRICK J.L. 1998. Reproductive Dominance of Pasture Trees in a Fragmented Tropical Forest Mosaic. SCIENCE Vol. 281 pp. 99 101. BUSH S.P. 2000. Clonal reproducti on through plant fragments in Poikiocanthus Macranthus. Ecology and Conservation of a Cloud Forest Monteverde. 3: 88. HEYN J. 1996. Vegetative Reproduction in three stages of succession. CIEE Fall. Pp. 32 40. MASTERS K. 2003, personal communication. NADKAR NI, N. 2000. Scope of past work. Ecology and Conservation of a Cloud Forest Monteverde. 1: 11. _______, 1999. Asexual Reproduction: An Alternative Strategy. Biology of Plants ed. 6. 9: 179. THE HUTCHINSON DICTIONARY, 11/27/ 2003. http://ask.elibrary.com 1/1/1998
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Reproduction of Besleria princeps in Monteverde Cloud Forests
Digitized by MVI
The purpose of this study was to show the occurrence of asexual versus sexual reproduction in lower
premontane cloud forest, on the Atlantic slope and the Pacific slope of the Tilarn Mountain range near the
Monteverde Biological Station. Eight hundred plants, 400 on the Atlantic slope and 400 on the Pacific side,
were examined at their roots for fragmentation and seeding. The elevations of each slope and a comparison
of the two slopes were examined using a chi-squared two-way contingency test.
The results showed that asexual reproduction (fragments) is more common in Besleria princeps
than sexual reproduction (from seeds). The Atlantic slope and the highest elevations of each slope, showed
a higher frequency of fragments to seeds in the windier and wetter conditions.
The chi-squared results of the Pacific slope elevations were significant, x = 29.609; df = 3, and a pvalue
<.0001. The Atlantic slope elevations chi squared test had significant results, x = 21.212, df = 2, and
a p-value <.0001. The results of the Atlantic slope versus the Pacific slope showed significant chi squared
results, x = 41.439, df = 1, and a p-value <.0001.
Text in English.
Costa Rica--Puntarenas--Monteverde Zone
Costa Rica--Puntarenas--Zona de Monteverde
Tropical Ecology Fall 2003
Ecologa Tropical Otoo 2003
t Monteverde Institute : Tropical Ecology