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Within-crown asynchrony of Ficus pertusa (Moraceae) Hannah Lippe Department of Biology, Brown University ABSTRACT Well-supported theory says that populations of Ficus species reproduce asynchronously across population s and synchronously within individual trees. However, recent studies in the Monteverde area have found e vidence for within-crown asynchrony for Ficus tuerckheimii a large strangler fig, and hinted at within-crown asynchrony for Ficus pertusa a small free-standing tree. I tested the predict ion that fig tree populations are asynchronous and individuals are synchronous by looking at fifteen F. pertusa trees with fruits. I looked for microclimate effe cts on flowering synchrony as a result of uneven sun expos ure within a crown. As predicted, the population w as asynchronous, but 13 out of the 15 trees displayed within-crown asynchrony. The interval distance bet ween successive development stages was never greater tha n two, showing that asynchrony is slight. No consi stent trends were found across positions, indicating that sun ex posure may not create a differential in syconia dev elopment. Microclimate effects did not influence asynchrony, suggesting that within-crown asynchrony, a supposed anomaly, could be an adaptive consequence of other physiolog ical or ecological factors. RESUMEN La teora bien apoyada dice que Ficus spp. se reproduce asncronamente a travs de poblacione s y sncronamente dentro de rboles individuales. Sin e mbargo, estudios recientes en el rea de Monteverde han encontrado evidencia de asincrona dentro del dosel para Ficus tuerckheimii un higuern grande y estrangulador, e insinuado que hay asincrona dentro del dosel en Ficus pertusa un rbol pequeo y autoestable. Prob la predicci n que esas poblaciones de higueras son asncronas y l os individuos son sncronos por investigar quince rboles de F. pertusa con frutas. Busqu efectos del microclima en la s incronizacin a consecuencia de exposicin desigual de sol dentro del dosel. Como predije, la poblacin fu e asncrona, pero 13 de los 15 rboles demostraron la asincrona dentro del dosel. La distancia del intervalo entre etapas sucesivas de desarrollo nunca fue ms que do s, mostrando que la asincrona es leve. Ningunas tendencias coh erentes fueron encontradas a travs de posiciones, indicando que la exposicin de sol no crea un diferencia en el de sarrollo del siconio. Los efectos del microclima no influyeron la asincrona, sugiriendo que la asincrona dentro del dosel, una anomala supuesta, podra ser una conse cuencia de otros factores fisiolgicos o ecolgicos. INTRODUCTION The phenology of Ficus spp. (Moraceae) is unusual in tropical communities as populations of fig trees produce fruits all year ro und. Each species of fig is involved in an obligate mutualism with a species-specific wasp (Hy menoptera, Chalcidoidae, Agaonidae) in which the wasp pollinates the fig flowers and the f ig provides ovules as sustenance for wasp larvae (Janzen 1979). Wasp development generally o ccurs in synch with syconia development, with larvae laid in very young figs and mature fema le wasps emerging from ripe figs (Bronstein 1987). The entire life cycle of the wasps occurs i nside the syconia except for the female dispersal phase, in which adult females leave their natal syconia to find new domicile for their own eggs, bringing the pollen from one tree to anot her. In order for the population of wasps to reproduce, the population of fig trees must always have syconia of all developmental stages so
that a searching wasp can find a receptive fig. Li terature on fig phenology says that populations must flower asynchronously to maintain the wasp pop ulations, but individual trees must be synchronous to ensure outcrossing of pollen (Bronst ein 1992). Synchronous flowering forces wasps to bring pollen to another tree with receptiv e figs, and it maximizes the pheromones produced to attract wasps (Bronstein 1987). Despite the advantage that individual synchrony con fer, many Ficus species have been documented with asynchronous within-crown reproduct ion (Bronstein 1992). Two studies in Monteverde, Costa Rica, find that Ficus tuerckheimii a common strangler fig, exhibits withincrown asynchrony (Ling 2000 & pers. obs.). This an omaly may be a response to isolation by distance to other trees or harsh environmental cond itions threatening wasp populations. The tree flowers asynchronously to provide receptive syconia for the wasps despite sacrificing pollen outcrossing (Janzen 1979). Within-crown asynchrony ma y also result from a composite of several strangler trees giving different genetic instructio ns for reproductive phenology (Thomson et al. 1997). Additionally, a study on eight Ficus pertusa trees in Monteverde finds a difference in developmental stages between inner and outer crown syconia within individual trees, which may result from differential microclimate effects, like light availability, in a single tree (Mwampamba 1998). Uneven sunlight in a crown could catalyze t he development of select syconia, resulting in variable rates of growth. Given the results of these studies, I tested the pr ediction that individual fig trees flower synchronously. I looked more rigorously at the pop ulation of F. pertusa in Monteverde with a larger sample size and across a larger geographic r ange than used in the Mwampamba (1998) study. Ficus pertusa has high densities in Monteverde, in part because they are planted as living fenceposts, allowing me to eliminate the possibilit y that isolated wasp populations favor withincrown asynchrony, and the genetic composite hypothe sis as an explanation for individual asynchrony. This allowed me to focused on microcli mate effects from differential sun exposure causing asynchrony in individual trees, predicting that I would find more developed syconia in parts of the crown with more sun exposure. METHODS Study Site and Species Ficus pertusa is a small hemiepiphytic or free-standing tree and one of the two most common Ficus species in Central America. It is found from 0-20 00m in moist highland to lowland forests in disturbed and undisturbed habita ts (Bronstein 1987). The species is particularly common to the Monteverde region becaus e it has been planted here as living fence posts and grows abundantly in pastures and remnant forest. I found 30 F. pertusa trees along roadsides, pastures, and residences from San Luis t o Cerro Plano, and a total of 15 had syconia at variable developmental stages. Obtaining and processing figs
From each of the 15 trees, I selected figs from the cardinal points of the crown and from the outer crown (sun) and the inner crown (shade). I chose these six positions assuming that syconia on the east and west sides of the tree rece ived more direct sun than those on the north and south, and that syconia on the outer crown woul d also receive more sun than those in the shaded inner crown. I used a pole pruner to reach high branches with figs, but sometimes I could only obtain figs from the basal branches. I attemp ted to get 20 syconia from each position per tree, but several trees either had zero or less tha n 20 figs. I obtained 120 figs from ten trees while the other five trees yielded between 24-130 f igs per tree. For each syconium, I measured the diameter at the widest point, cut the fig open, and evaluated the developmental stage. To determine the stage, I used criteria established by Thompson et. al (1997) that characterized the developmental stages of syconia from five other Ficus species, but I adapted this system to Ficus pertusa (Table 1). Population level asynchrony To test the prediction that fig populations are asy nchronous, I constructed a frequency distribution of the developmental stages across the 15 trees with syconia, but omitted the 15 without syconia. Given that there was variability in the length of time the trees had been without figs, I could not classify the trees as a single st age and so did not incorporate these trees into the analysis. Tree level asynchrony To determine differences in the average size and st age across positions in individual trees, I ran a one-way ANOVA test for each of the f ifteen trees. For each tree, I also calculated the interval distances, meaning the number of diffe rences between stages. For example, if a tree had syconia at Stages Four, Five, and Six, its inte rval distance was two. This distance shows how far apart the syconia are in development on a s ingle tree. Comparing F. pertusa to F. tuerckheimii I calculated the mean overall asynchrony for the fi fteen trees using an index of asynchrony to compare the asynchrony of F. pertusa to the asynchrony that Ling (2000) found in F. tuerckheimii The asynchrony index (A) is the measure of the d iversity of the developmental stages present in an individual tree. The original equation for this index was constructed for evaluating five developmental stages and used the s ymbol E instead of A (Bronstein 1992). I modified the equation to account for six stages and to specifically address asynchrony. Asynchrony is calculated as where a through e is proportion of syconia in devel opmental stages 1 through 6, respectively. Asynchrony runs from 1 to 0, with maximum asynchron y (=1) occurring when a tree contains all six stages in equal proportions and minimum asynchr ony (=0) occurring when all syconia in a crown are at a single stage. I calculated the over all asynchrony of each tree by pooling all e i=a A = 1 [i-0.16667] 1.6667
syconia of a tree together. I then found the mean overall asynchrony for the F. pertusa population. I also compared the two species async hrony based on personal observations of interval distances between syconia in a single F. tuerckheimii tree. I did not compare interval distances to the results from the Ling (2000) study because the syconia were evaluated using different criteria. RESULTS Population level asynchrony As predicted, all six stages of syconia were presen t in the fifteen fruiting trees (Fig. 1). Stage Four syconia were found in the most number of trees while Stage One syconia were found in the least number of trees. Tree level asynchrony My results showed significant asynchrony within thi rteen out of the fifteen individuals. Two trees had syconia at Stages One, Two, and Three three trees had both Stages Four and Five, and four trees had Stages Four, Five, and Six. Usi ng diameter as another measurement of asynchrony besides showed more precise syconia vari ability within a tree. Six trees were completely synchronous when measured as stages, but five out of those six trees had asynchrony when measured by size (Table 2 and 3). The largest interval distance, the number of differences between stages represented, was two for any tree. Low interval distance showed that although there was asynchrony, stage differentials were smal l within crowns. However, there were no consistent trends across positions in the crown, as no single position consistently had the largest or most developed syconia. Microclimates in cardin al directions or inner and outer crown positions influenced the pattern of asynchrony with in a tree (Fig. 2). Comparing F. pertusa to F. tuerckheimii The mean overall asynchrony for all fifteen trees w as 0.15 0.15 (mean SD). Ling (2000) found that the mean overall asynchrony of fo ur F. tuerckheimii trees was 0.26 0.06. My personal observations of asynchrony in F. tuerckheimii revealed that a single F. tuerckheimii tree had an interval distance of five, compared to the maximum two interval distances for F. pertusa. These data show that F. tuerckheimii has more syconia at different stages within a crown that are farther apart in their development t han F. pertusa Additional observations As I was collecting figs, I noted that later stage figs were often on branches without leaves. Four of the seven trees with Stage Five sy conia did not have leaves on the branches with figs. DISCUSSION
Within-crown asynchrony was present in F. pertusa individuals, so to a certain extent, I rejected the hypothesis that the fig tree and fig w asp life cycles depend on population asynchrony and individual synchrony. The mutualism was not ne cessarily disrupted because early stage syconia were never found in a tree with later stage s. Self-pollination would not be a possibility for the trees because the wasps were still forced t o find another tree. I also concluded that microclimate effects from sun exposure did not infl uence asynchrony, as there was no consistent trend of asynchrony across positions in the crown. The lack of obvious microclimate effects implies that other pressures cause slight within-cr own asynchrony in F. pertusa Herre (1996) proposes that resource limitation may explain the slight asynchrony found in both stages and sizes of figs within crowns. Re source availability could limit a fig trees ability to engage in simultaneous vegetative growth and reproduction under times of stress. A resource-constrained individual could choose to put its nutrients into either its leaves or figs, or i t could allocate resources to a subset of the syconia crop and leave others dormant for a period of time to allow for simultaneous vegetative growth. Adaptive pulses of resources to alternating subsets of syconia in a crown could create a slight ly asynchronous pattern of syconia development. The slightly asynchronous crown in so me F. pertusa individuals could thus be a result of constrained resources. The observation t hat four of the seven trees did not have leaves on branches with Stage Five syconia, a highly resou rce-expensive stage, suggests that some F. pertusa trees are indeed constrained by resources. All fo ur of these trees demonstrated asynchrony, indicating that this resource limitatio n may have also impacted the rate of syconia development. However, not all of the trees with St age Five syconia dropped their leaves, showing that resource allocation may be a plastic t rait available to fig trees when needed (Herre 1996). The ability to allocate resources adaptively under stressful conditions may be a trait utilized often by species that are particularly con strained. These species would then display more within-crown asynchrony. Ficus tuerckheimii has a higher mean overall asynchrony than F. pertusa and is arguably a more resource-constrained specie s. Ficus tuerckheimii is a larger tree and more commonly found in the forest canopy, where light competition is higher. Ficus tuerckheimii is also a strangler fig, so it spends part of its life out of contact with the ground where access to water and nutrients is limited, whe reas F. pertusa is free-standing. Syconia within a crown may be farther apart in their develo pment in F. tuerckheimii because it goes through longer periods of resource deprivation than F. pertusa The allocation of resources under stressed conditio ns may force trade-offs between vegetative and reproductive growth in F. pertusa but it could also be adaptive for maintaining the fig and wasp mutualism. While forcing pollen o utcrossing, the slight asynchrony would also enable a more stable population of wasps. Receptiv e figs would be produced for a longer period of time rather than all at once, so it is more like ly that a wasp would find a receptive fig. It would also reduce competition between female wasps for receptive figs because they do not all emerge from ripe figs at the same time. The tradeoffs made in F. pertusa between could benefit the fig and wasp mutualism, but the more stressed Ficus tuerckheimii has a larger stage differential that could be detrimental to the tree. Thus, resource allocation is not always adaptive for the mutualism, but the plasticity of the trait enables some individuals or species to gain beneficial asynchrony while making trade-offs under stressed conditions. The slight asynchrony in F. pertusa might also be influenced by the three-week period o f receptivity for young syconia (Anstett 1996). Syconia initiate all at on e once within a crown and send out chemical signals to attract its pollinatin g wasps (Bronstein 1987). Wasp entry into the
receptive fig cues further development in the sycon ia when the wasp pollinates the flower and oviposits eggs (Bronstein 1992). During the threeweek receptive period, size becomes independent of stage. The unpollinated syconia wil l continue to grow in size but not mature in stage, while the syconia pollinated early in the re ceptivity period will stop growing and begin to mature in synch with the wasp larvae (Bronstein 198 8). Pollination events occurring throughout a receptive period would then create differentials within a crown for both sizes of figs and stages. The 13 asynchronous F. pertusa trees showed variability of both size and stage wi thin a crown. The timing of pollination could therefore explain t he asynchrony and the small interval distances, as a three-week difference in development would pro duce only a small differential between stages. Again, this flowering pattern might enable a more stable wasp population while still forcing out-crossing of tree pollen. While the wasp pollinators are a major determining factor in fig fruiting phenology, fig dispersers may also influence the reproductive patt erns of F. pertusa (Kalko 1996). Kalko (1996) performed a study on Panamanian figs showing that bird dispersed fruits were often produced asynchronously within a crown. Bird-dispe rsed figs, like those of both F. pertusa and F. tuerckheimii are typically small, red, and odorless. Birds ar e visually oriented and are attracted by color rather than smell, like bats. A fig tree attempting to attract a bird does not need a large synchronous crop of figs to produce a strong smell; a less intense visual signal will suffice for attracting birds that are in sight of t he tree. Since no amount of synchrony increasing the visual signal will attract birds from a distanc e, slightly asynchronous flowering can conserve energy without sacrificing dispersal (Herre 1996). The observed asynchrony in both F. pertusa and F. tuerckheimii figs might then be at least partially explained by their disperser and an opportunity to conserve energy. The resource availability hypothesis, the long rece ptive period, and the influence of the disperser could all interact to produce the variabl e patterns of within-crown asynchrony in F. pertusa These explanations for within-crown asynchrony d emonstrate that slight asynchrony could enable energy conservation and more stable wa sp populations while still ensuring tree outcrossing. Within-crown asynchrony may in fact redu ce the minimum viable population of Ficus pertusa required to maintain the wasp population, creating a more efficient mutualism (Anstett 1996). Further studies should be done to see if sl ight within-crown asynchrony could in fact be advantageous to both the fig and wasp populations. ACKNOWLEDGEMENTS Thank you to Karen Masters for her knowledge of fig s, patient guidance, and teaching me to think like an ecologist. Thank you to Pablo All en for help with statistics and answering every one of the questions I asked. Thank you to Alan Ma sters for the inspiration for this project. Thank you to all the people who pointed me towards a tree during my fig hunt, and to all the property owners who allowed me to take figs from th eir trees. LITERATURE CITED Anstett, M.C., F. Kjellberg, and J.L. Bronstein. 19 96. Waiting for wasps: consequences for the pollin ation dynamics of Ficus pertusa L. Journal of Biogeography 23: 459-466.
Bronstein, J.L. 1987. Limits to fruit production i n a monoecious fig: consequence of an obligate mutu alism. Ecology 69: 207-214. Bronstein, J.L. and A. Patel. 1992. Causes and con sequences of within-tree phonological patterns of t he Florida strangling fig, Ficus aurea (Moraceae). American Journal of Botany 79: 41-48. Herre, E. A. 1996. An overview of studies on a com munity of Panamanian figs. Journal of Biogeography 23: 593607. Janzen, D. H. 1979. How to Be a Fig. Annual Revie w of Ecology and Systematics 10: 13-51. Kalko, E.K.V., E. A. Herre, and C.O. Handley, Jr. 1 996. Relation of fig fruit characteristics to fruit -eating bats in the New and Old World tropics. Journal of Biogeography 23: 565-567. Ling, S. C. 2000. Within-tree flowering synchrony i n Ficus tuerckheimii (Moraceae). UCEAP Monteverde Tropical Biology, Spring. Mwampamba, T. H. 1998. Fig flowering and fruiting phenology. CIEE Tropical Ecology and Conservation, Fall. Thomson, J.D., S. Dent-Acosta, P. Escobar-Pramo, a nd J.D. Nason. 1997. Within-crown flowering synchr ony in strangler figs, and its relationship to allofusion. Biotropica 29: 291-297. Table 1. Criteria used to characterize reproductiv e stage based on development of flowers, seeds, and wasp offspring. Reproductive Stage Defining characteristics Stage One Buds
Stage Two Foundressing moving in syconia Stage Three Seeds and offspring beginning to develop, foundresses dead Stage Four Seeds and offspring developing, stigmas brownish and tightly packed Stage Five Syconia ripening, Stage Six Figs fully ripened, ready for dispersal Figure 1. Frequency distribution of the six differe nt developmental stages. Syconia of all six stages of development are found in 15 trees of the Ficus pertusa populuation in Monteverde, showing that the population has asynchr onous flowering. Table 2. Mean size (cm), mean stage, standard devia tions, and sample size for syconia from positions north, east, and west in each tree. Tree North East South West F p
1 Size 0.89 0.814 0.888 0.8845 1.83 0.151 SD 0.06 0.03 0.08 0.06 N 20 5 20 20 Stage 5.20 5.40 5.05 5.00 3.41 0.02 SD 0.41 0.55 0.22 0.00 N 20 5 20 20 2 Size 0.82 0.71 0.81 0.86 15.85 <.0001 SD 0.06 0.10 0.07 0.05 N 20 20 20 20 Stage 4.00 3.95 4.00 4.00 1.00 0.4 SD 0.00 0.22 0.00 0.00 N 20 20 20 20 3 Size 0.96 1.03 3.24 0.1 SD 0.03 0.13 N 0 0 9 5 Stage 4.00 4.20 1.93 0.2 SD 0.00 0.45 N 0 0 9 5 4 Size 0.76 0.74 0.72 0.61 7.48 0.0002 SD 0.13 0.05 0.07 0.15 N 20 20 20 20 Stage 2.50 2.10 1.80 1.80 6.63 0.0005 SD 0.51 0.64 0.52 0.62 N 20 20 20 20 5 Size 0.83 0.85 0.85 0.79 6.63 0.0005 SD 0.04 0.05 0.04 0.14 N 20 20 20 20 Stage 4.10 4.00 4.00 4.00 1.00 0.4 SD 0.45 0.00 0.00 0.00 N 20 20 20 20 6 Size 0.90 1.04 1.03 0.93 15.66 <.0001 SD 0.07 0.09 0.08 0.06 N 20 20 20 20 Stage 5.00 5.15 4.60 4.45 10.10 <.0001 SD 0.00 0.59 0.50 0.51 N 20 20 20 20 7 Size 0.97 0.92 0.90 0.95 2.56 0.1 SD 0.07 0.06 0.04 0.15 N 20 20 20 20 Stage 4.00 4.00 4.00 4.00 SD 0.00 0.00 0.00 0.00 N 20 20 20 20 8 Size 0.92 0.89 0.88 0.96 2.47 0.1 SD 0.08 0.07 0.04 0.18 N 20 20 20 20 Stage 4.00 4.00 4.00 4.00 SD 0.00 0.00 0.00 0.00 N 20 20 20 20 9 Size 1.16 1.12 1.12 0.92 0.4
SD 0.06 0.13 0.11 N 20 20 0 20 Stage 5.05 4.80 4.85 1.86 0.2 SD 0.22 0.62 0.37 N 20 20 0 20 10 Size 0.92 0.91 0.92 0.93 0.12 1 SD 0.09 0.06 0.07 0.12 N 20 20 20 20 Stage 4.00 4.00 4.00 4.05 1.00 0.4 SD 0.00 0.00 0.00 0.22 N 20 20 20 20 11 Size 0.76 0.80 0.66 0.85 56.42 <.0001 SD 0.06 0.05 0.03 0.05 N 20 20 20 20 Stage 4.00 4.00 4.00 4.00 SD 0.00 0.00 0.00 0.00 N 20 20 20 20 12 Size 0.53 0.51 0.55 0.52 1.47 0.03 SD 0.07 0.07 0.18 0.14 N 30 20 30 20 Stage 1.87 2.10 1.80 1.85 1.08 0.2 SD 0.35 0.31 0.76 0.81 N 30 20 30 20 13 Size 1.15 1.25 1.28 3.81 0.5 SD 0.15 0.14 0.17 N 0 20 13 20 Stage 4.15 5.23 4.75 27.83 <.0001 SD 0.37 0.44 0.44 N 20.00 13.00 20.00 14 Size 0.79 0.77 0.81 0.77 3.26 0.7 SD 0.05 0.04 0.06 0.06 N 20 20 20 20 Stage 4.00 4.00 4.00 4.00 SD 0.00 0.00 0.00 0.00 N 20 20 20 20 15 Size 1.16 1.19 1.15 1.12 0.82 0.03 SD 0.19 0.08 0.14 0.13 N 20 20 20 20 Stage 4.90 5.20 5.20 4.90 1.52 0.2 SD 0.45 0.52 0.83 0.64 N 20 20 20 20 Table 3. Mean size (cm), mean stage, standard deviations, and sample size for syconia from sun and shade positions in each tree.
TreeSunShadeFp 1 Size 0.89 0.92 1.70 0.2 SD 0.08 0.06 N 20 20 Stage 5.15 5.05 1.09 0.3 SD 0.37 0.22 N 20 20 2 Size 0.76 0.84 17.95 0.0001 SD 0.07 0.06 N 20 20 Stage 3.95 4.00 SD 0.22 0.00 N 20 20 3 Size 1.07 1.11 0.16 0.7 SD 0.19 0.15 N 5 5 Stage 4.00 4.00 SD 0.00 0.00 N 5 5 4 Size 0.70 0.78 13.53 0.0007 SD 0.06 0.08 N 20 20 Stage 1.90 2.55 18.35 0.0001 SD 0.45 0.51 N 20 20 5 Size 0.85 0.83 25.67 <.0001 SD 0.04 0.05 N 20 20 Stage 4.00 4.00 7.89 0.008 SD 0.00 0.00 N 20 20 6 Size 0.92 1.00 25.67 <.0001 SD 0.05 0.05 N 20 20 Stage 4.20 4.65 7.89 0.008 SD 0.52 0.49 N 20 20 7 Size 0.89 0.86 1.62 0.2 SD 0.06 0.05 N 20 20 Stage 4.00 4.00 SD 0.00 0.00 N 20 20 8 Size 0.94 0.87 10.07 0.003 SD 0.08 0.05 N 20 20 Stage 4.00 4.00 SD 0.00 0.00
N 20 20 9 Size 1.03 1.09 1.27 0.3 SD 0.08 0.23 N 20 20 Stage 4.85 4.45 8.11 0.007 SD 0.37 0.51 N 20 20 10 Size 1.00 0.93 4.81 0.03 SD 0.13 0.07 N 20 20 Stage 4.60 4.00 28.50 <.0001 SD 0.50 0.00 N 20 20 11 Size 0.85 0.70 127.26 <.0001 SD 0.03 0.05 N 20 20 Stage 4.00 4.00 SD 0.00 0.00 N 20 20 12 Size 0.68 0.58 6.88 0.01 SD 0.13 0.13 N 20 20 Stage 2.50 2.55 0.05 8 SD 0.69 0.69 N 20 20 13 Size 1.16 1.22 2.21 0.1 SD 0.05 0.14 N 14 17 Stage 4.07 4.47 6.87 0.01 SD 0.27 0.51 N 14 17 14 Size 0.77 0.89 50.13 <.0001 SD 0.04 0.06 N 20 20 Stage 4.00 4.00 SD 0.00 0.00 N 20 20 15 Size 1.19 1.21 0.65 0.4 SD 0.11 0.09 N 20 20 Stage 5.45 4.90 6.13 0.02 SD 0.69 0.72 N 20 20
n n n n nrnn r rnn r r nn nn Figure 2. The number of times that north, east, so uth, or west and sun or shade has either the largest, second largest, third largest, or four th largest syconia (A, C, respectively) or most developed, second most developed, third most d eveloped, or least developed syconia (B, D, respectively). No position consiste ntly occupies a rank, showing that sun exposure does not influence within-crown asynchrony in Ficus pertusa
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Dentro de la sincrnica corona de Ficus pertusa (Moraceae)
Within-crown asynchrony of Ficus pertusa (Moraceae)
Well-supported theory says that populations of Ficus species reproduce asynchronously across populations and synchronously within individual trees. However, recent studies in the Monteverde area have found evidence for within-crown asynchrony for Ficus tuerckheimii, a large strangler fig, and hinted at within-crown asynchrony for Ficus pertusa, a small free-standing tree. I tested the prediction that fig tree populations are asynchronous and individuals are synchronous by looking at fifteen F. pertusa trees with fruits. I looked for microclimate effects on flowering synchrony as a result of uneven sun exposure within a crown. As predicted, the population was asynchronous, but 13 out of the 15 trees displayed within-crown asynchrony. The interval distance between successive development stages was never greater than two, showing that asynchrony is slight. No consistent trends were found across positions, indicating that sun exposure may not create a differential in syconia development. Microclimate effects did not influence asynchrony, suggesting that within-crown asynchrony, a supposed anomaly, could be an adaptive consequence of other physiological or ecological factors.
La teora bien apoyada dice que Ficus spp. se reproduce asncronamente a travs de poblaciones y sncronamente dentro de los rboles individuales. Sin embargo, estudios recientes en el rea de Monteverde han encontrado evidencia de asincrona dentro del dosel para Ficus tuerckheimii, un higuern grande y estrangulador, e insinuado que hay asincrona dentro del dosel en Ficus pertusa, un rbol pequeo y auto estable. He probado la prediccin de que las poblaciones de higuerones son asncronas y los individuales son sincrnicos por haber observado a los quince rboles F. pertusa con frutas.
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