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Seedling Mortality (seedling + mortality)
Selected AbstractsSeedling Mortality and Herbivory Damage in Subtropical and Temperate Populations: Testing the Hypothesis of Higher Herbivore Pressure Toward the TropicsBIOTROPICA, Issue 2 2010Ek Del-Val ABSTRACT Herbivory rates are generally thought to be higher in tropical than in temperate forests. Nevertheless, tests of this biogeographic prediction by comparing a single plant species across a tropical-temperate range are scarce. Here, we compare herbivore damage between subtropical and temperate populations of the evergreen tree Aextoxicon punctatum (Olivillo), distributed between 30° and 43° S along the Pacific margin of Chile. To assess the impact of herbivory on Olivillo seedlings, we set up 29 experimental plots, 1.5 × 3 m: 16 in forests of Fray Jorge National Park (subtropical latitude), and 13 in Guabún, Chiloé Island (temperate latitude). Half of each plot was fenced around with chicken wire, to exclude small mammals, and the other half was left unfenced. In each half of the plots we planted 16 seedlings of Olivillo in December 2003, with a total of 928 plants. Seedling survival, leaf production and herbivory by invertebrates were monitored over the next 16 mo. Small mammal herbivores killed ca 30 percent of seedlings in both sites. Nevertheless, invertebrate herbivory was greater in the temperate forest, thus contradicting the expected trend of increasing herbivore impact toward the tropics. Seedling growth was greater in subtropical forest suggesting better conditions for tree growth or that higher invertebrate herbivory depressed seedling growth in the temperate forest. Invertebrate herbivory increased toward temperate latitudes while small mammal herbivory was similar in both sites. We suggest that comparison of single species can be useful to test generalizations about latitudinal patterns and allow disentangling factors controlling herbivory patterns across communities. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source] Population dynamics of an endangered heathland shrub, Epacris stuartii (Epacridaceae): Recruitment, establishment and survivalAUSTRAL ECOLOGY, Issue 1 2002David A. Keith Abstract The only known population of the endangered shrub Epacris stuartii Stapf was studied from 1994 to 2001 using demographic census techniques. The effects of substrate, a fire and a storm on the emergence and survival of seedlings and the survival of established plants of different sizes were examined using failure-time analyses and logit-linear models. Ninety-five per cent of seedling emergence was delayed until the second post-fire spring, an unusual response among species with persistent soil seed banks. Mortality of seedlings was extreme compared with larger-seeded species, but diminished significantly with age. Seedling mortality varied significantly between substrates: 40% of seedlings persisted for more than 5 years in mineral soil, whereas less than 10% lived more than a year on rock and intermediate substrates. However, seedling numbers and local densities were lower on soils than other substrates. Background mortality of established plants was lower on soil and intermediate substrates (0.5% per year) than on rock (3% per year). Small plants may be more susceptible than large plants on rock, but not on soil. Both the fire and the storm resulted in elevated mortality of established plants. The population exhibited a variable response to fire, with plants on rock and intermediate substrates behaving as obligate seeders, whereas plants in soil resprouted. This appears to be the first report of microhabitat variation in fire response at sympatric scales. The effects of the storm were apparently independent of substrate and plant size. The essentially independent disturbance regimes comprising recurring fires and storms are likely to have a profound effect on the long-term population dynamics of E. stuartii. Over the 7-year census period, recruitment has failed to compensate for mortality, resulting in a 30% net decline in the population. The demographic census has proved to be crucial in the detection and diagnosis of this decline. [source] Forest Elephants: Tree Planters of the CongoBIOTROPICA, Issue 4 2009Stephen Blake ABSTRACT The abundance of large vertebrates is rapidly declining, particularly in the tropics where over-hunting has left many forests structurally intact but devoid of large animals. An urgent question then, is whether these ,empty' forests can sustain their biodiversity without large vertebrates. Here we examine the role of forest elephant (Loxodonta africana cyclotis) seed dispersal in maintaining the community structure of trees in the Ndoki Forest, northern Congo. Analysis of 855 elephant dung piles suggested that forest elephants disperse more intact seeds than any other species or genus of large vertebrate in African forests, while GPS telemetry data showed that forest elephants regularly disperse seeds over unprecedented distances compared to other dispersers. Our analysis of the spatial distribution of trees from a sample of 5667 individuals showed that dispersal mechanism was tightly correlated with the scale of spatial aggregation. Increasing amounts of elephant seed dispersal was associated with decreasing aggregation. At distances of<200 m, trees whose seeds are dispersed only by elephants were less aggregated than the random expectation, suggesting Janzen,Connell effects on seed/seedling mortality. At the landscape scale, seed dispersal mode predicted the rate at which local tree community similarity decayed in space. Our results suggest that the loss of forest elephants (and other large-bodied dispersers) may lead to a wave of recruitment failure among animal-dispersed tree species, and favor regeneration of the species-poor abiotically dispersed guild of trees. [source] Grazing and community structure as determinants of invasion success by Scotch broom in a New Zealand montane shrublandDIVERSITY AND DISTRIBUTIONS, Issue 1 2003P. J. Bellingham Abstract. Scotch broom (Cytisus scoparius (L.) Link; Fabaceae) is a problematic invasive plant in many countries, and while attention has been paid to traits that make it a successful invader, there has been less focus on the properties of ecosystems that it invades. We conducted an experiment in a New Zealand montane shrubland with tussock grasses that has been invaded by Scotch broom to determine features that rendered it susceptible to invasion. We planted broom seedlings into the shrubland (control) and into three treatments: (1) resident shrubs removed, (2) tussocks removed and (3) shrubs and tussocks removed. We measured broom seedling mortality and growth over two growing seasons. The site was grazed by sheep in the first season, and scarcely grazed in the second, wetter season. Survivorship across all treatments after 19 months was 42%, and was lowest where shrubs were retained but tussocks removed. Broom seedlings grew taller and had greater leaf areas in treatments that retained shrubs. Neighbouring (within 49 cm) shrubs had no effects on survivorship or growth of broom seedlings. Neighbouring tussocks increased survivorship of broom seedlings but depressed their growth. Grazing by sheep was the most important determinant of survivorship and growth of broom seedlings, and effects were uniform regardless of experimental treatments. Initial high mortality of seedlings (48% in the first 3 months) was due to grazing, and height growth was often negative during periods of grazing. In the second growing season when the site was less grazed and there was greater rainfall, there was a rapid increase in height across all treatments. Continued grazing of the site by sheep is likely to be the chief means of retarding the invasion. [source] Pathogenicity of Fusarium verticillioides and Fusarium oxysporum on Pinus nigra seedlings in northwest SpainFOREST PATHOLOGY, Issue 2 2008P. Martín-Pinto Summary Fusarium verticillioides may be responsible for causing significant damping-off damage similar to that incited by F. oxysporum on forest seedlings, resulting in considerable losses in nurseries in northwest of Spain. Traditionally, F. oxysporum has been considered the most important agent of this disease in Spanish forest nurseries. However, recent studies have showed that F. verticillioides also has been frequently isolated from diseased plants. This has increased the necessity for a more comprehensive knowledge of the behaviour and pathogenicity of both Fusarium spp. isolated from these sites. The effect of Fusarium spp. on seed germination and on seedling mortality was analysed by inoculating the fungus at seeding. The in vitro growth of the two species was studied and is discussed in relation to in vivo virulence. Both species caused a reduction in seed germination and an increase in seedling mortality. Mortality caused by F. verticillioides treatments occurred sooner than that for F. oxysporum and the growth rate of F. verticillioides was also greater. [source] Rooting depth and soil moisture control Mediterranean woody seedling survival during droughtFUNCTIONAL ECOLOGY, Issue 3 2007F. M. PADILLA Summary 1Seedling survival is one of the most critical stages in a plant's life history, and is often reduced by drought and soil desiccation. It has been hypothesized that root systems accessing moist soil layers are critical for establishment, but very little is known about seedling root growth and traits in the field. 2We related seedling mortality to the presence of deep roots in a field experiment in which we monitored soil moisture, root growth and seedling survival in five Mediterranean woody species from the beginning of the growing season until the end of the drought season. 3We found strong positive relationships between survival and maximum rooting depth, as well as between survival and soil moisture. Species with roots in moist soil layers withstood prolonged drought better, whereas species with shallow roots died more frequently. In contrast, biomass allocation to roots was not related to establishment success. 4Access to moist soil horizons accounted for species-specific survival rates, whereas large root : shoot (R:S) ratios did not. The existence of soil moisture thresholds that control establishment provides insights into plant population dynamics in dry environments. [source] Mortality in seedling populations of Silver Birch: genotypic variation and herbivore effectsFUNCTIONAL ECOLOGY, Issue 5 2003K. Prittinen Summary 1Variation among mature plants reflects mortality that has occurred during the seedling phase. Our earlier studies have shown variation in resistance to insect and vole herbivory among Silver Birch genotypes that represent variation in a naturally regenerated birch stand. The aim of this study was to examine whether seedling mortality varied among these genotypes, and whether insect and field vole herbivory affected mortality. The 20 genotypes studied competed with each other in dense stands, which were randomly assigned to insect and vole exposure and fertilization treatments. 2Insect herbivory and fertilization increased mortality significantly (by 98 and 68%, respectively). The fertilization effect was probably due to accelerated self-thinning among fast-growing seedlings. Although vole browsing removed considerable biomass, it did not affect seedling mortality. 3Mortality was context-dependent. The genotypes differed both in their overall mortality and in their response to insect herbivory. However, the effect of insects on a genotype depended more on its success in competition than on its resistance: even small amounts of feeding were detrimental to short, shaded seedlings, while taller seedlings in the canopy were affected less, although they were eaten more. 4It is concluded that moderate levels of insect herbivory can increase seedling mortality considerably. Furthermore, herbivory can change the genetic structure of birch populations through selective mortality, which in dense stands is dependent on competitive traits. [source] Natural regeneration and population dynamics of the tree Afzelia quanzensis in woodlands in Southern AfricaAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Karin Gerhardt Abstract The logging of tree species of high commercial value is increasing throughout the African continent, yet the ecology of these species is generally poorly known. We studied the regeneration pattern and size class distribution of Afzelia quanzensis populations in northern South Africa over a 5-year period. Recruitment was low as the annual seedling mortality was >65%. Seedlings were located under the canopy and were affected by drought and browsing. The adults were scattered or were in a clump-dispersed pattern, which would result in higher recruitment of offspring near parents. Individuals of 0,10 cm diameter at breast height (DBH) were few, while there were 32 trees ha,1 at >10 cm DBH with an annual mortality of 0.8%. Annual diameter increments varied between 0.06 and 0.28 cm. It appears that the transition from the sapling into the juvenile stage could be a bottleneck in the regeneration of the species. A longer study, including more rainfall cycles, may reveal other patterns as dry and wet years have different impacts on dynamics. Résumé La coupe d'espèces d'arbres de grande valeur commerciale augmente dans tout le continent africain, pourtant l'écologie de ces espèces est généralement mal connue. Nous avons étudié le schéma de régénération et la distribution des classes d'âge des populations d'Afzelia quanzensis dans le nord de l'Afrique du Sud pendant cinq ans. Le recrutement était faible car la mortalité annuelle des jeunes plants était de plus de 65%. Les jeunes plans se trouvaient sous la canopée et étaient affectés par la sécheresse et par le broutage des animaux. Les adultes étaient dispersés ou se trouvaient en un schéma en bosquet, qui résulte en un plus fort recrutement de la progéniture près des parents. Les individus de 0,10 cm DBH étaient rares, alors qu'il y avait32 arbres ha,1à >10 cm DBH, avec une mortalité annuelle de 0,8%. L'incrément annuel du diamètre variait entre 0,06 et 0,28 cm. Il semble que la transition entre le stade de jeune arbre et celui de juvénile pourrait bien constituer un étranglement dans la régénération de l'espèce. Une étude plus longue, comprenant plus de cycles de pluies, pourrait révéler un autre schéma étant donné que les années sèches et humides ont des impacts différents sur cette dynamique. [source] Virus infection and grazing exert counteracting influences on survivorship of native bunchgrass seedlings competing with invasive exoticsJOURNAL OF ECOLOGY, Issue 2 2006C. M. MALMSTROM Summary 1,Invasive annual grasses introduced by European settlers have largely displaced native grassland vegetation in California and now form dense stands that constrain the establishment of native perennial bunchgrass seedlings. Bunchgrass seedlings face additional pressures from both livestock grazing and barley and cereal yellow dwarf viruses (B/CYDVs), which infect both young and established grasses throughout the state. 2,Previous work suggested that B/CYDVs could mediate apparent competition between invasive exotic grasses and native bunchgrasses in California. 3,To investigate the potential significance of virus-mediated mortality for early survivorship of bunchgrass seedlings, we compared the separate and combined effects of virus infection, competition and simulated grazing in a field experiment. We infected two species of young bunchgrasses that show different sensitivity to B/CYDV infection, subjected them to competition with three different densities of exotic annuals crossed with two clipping treatments, and monitored their growth and first-year survivorship. 4,Although virus infection alone did not reduce first-year survivorship, it halved the survivorship of bunchgrasses competing with exotics. Within an environment in which competition strongly reduces seedling survivorship (as in natural grasslands), virus infection therefore has the power to cause additional seedling mortality and alter patterns of establishment. 5,Surprisingly, clipping did not reduce bunchgrass survivorship further, but rather doubled it and disproportionately increased survivorship of infected bunchgrasses. 6,Together with previous work, these findings show that B/CYDVs can be potentially powerful elements influencing species interactions in natural grasslands. 7,More generally, our findings demonstrate the potential significance of multitrophic interactions in virus ecology. Although sometimes treated collectively as plant ,predators', viruses and herbivores may exert influences that are distinctly different, even counteracting. [source] Do spatial effects play a role in the spatial distribution of desert-dwelling Acacia raddiana?JOURNAL OF VEGETATION SCIENCE, Issue 4 2000Kerstin Wiegand Abstract. We investigated the spatial pattern of A. raddiana in the Negev desert of Israel in order to gain insights into the factors and processes driving the dynamics of this species. Using a scale-dependent measure, the ring statistic, we analysed both patterns observed in the field and time series of spatial tree distributions produced by a simulation model. In the field, random spacing was the predominant pattern observed. However seedlings were clumped on small scales. We ran the model under two contrasting scenarios representing hypotheses that explain the clumping of seedlings and the random distribution of trees. One hypothesis is that there is spatial heterogeneity in seed distribution, germination and seedling mortality, but that these heterogeneities are not correlated with each other in space. The second hypothesis assumes a correlation between these heterogeneities leading to areas suitable for establishment. However, the suitability of the sites is temporally variable. Furthermore, the second hypothesis assumes density-dependent tree mortality due to competition. Both hypotheses lead to spatial distributions that are in qualitative agreement with the patterns observed in the field. Therefore, the classical view that a clumped seedling distribution and a random pattern of older trees is due to clumped regeneration and density-dependent mortality may not hold for Acacia trees in the Negev. [source] RAPD variation and population genetic structure in Prunus mahaleb (Rosaceae), an animal-dispersed treeMOLECULAR ECOLOGY, Issue 9 2000Pedro Jordano Abstract We examined the patterns of random amplified polymorphic DNA (RAPD) variation among seven Prunus mahaleb (Rosaceae) populations extending over , 100 km2 to examine local differentiation in relation to spatial isolation due to both geographical distance and differences in elevation. No less than 51.4% of the RAPD loci were polymorphic, but very few were fixed and among-population variation accounted for 16.46% of variation in RAPD patterns. Mean gene diversity was 0.1441, with mean Nei's genetic diversity for individual populations ranging between 0.089 and 0.149. Mean GST value across loci was 0.1935 (range, 0.0162,0.4685), giving an average estimate for Nm of 1.191. These results suggest extensive gene flow among populations, but higher GST and lower Nm values relative to other outcrossing, woody species with endozoochorous dispersal, also suggest a process of isolation by distance. The combined effect of both geographical and elevation distances and nonoverlapping flowering and fruiting phenophases on the GST matrix was partially significant, revealing only marginal isolation of the P. mahaleb populations. The matrix correlation between estimated Nm values among populations and the geographical + elevation distance matrices (r = ,0.4623, P = 0.07), suggests a marginal trend for more isolated populations to exchange less immigrants. Long-distance seed dispersal by efficient medium-sized frugivorous birds and mammals is most likely associated to the high levels of within-population genetic diversity. However, vicariance factors and demographic bottlenecks (high postdispersal seed and seedling mortality) explain comparatively high levels of local differentiation. [source] Effects of watering regime and depth of burial on seedling emergence of four dominant psammophytes in the Mu Us sandy land, Inner Mongolia, China, and relevance to revegetation of a desertified regionANNALS OF APPLIED BIOLOGY, Issue 1 2009M.Q. Zheng Abstract Four dominant psammophyte species are air-seeded in attempts to revegetate the Mu Us sandy land in Inner Mongolia, but seedling emergence is low. This study sought to clarify the behaviour of seedling emergence under different water supply and sand burial regimes to improve the technology of air seeding. Seeds were buried in sand at depths of 0, 0.5, 1, 1.5, 2, 3 and 5 cm and supplied one time with 2.5, 5, 7.5, 10, 15, 20, 30 or 40 mm of water or with 2.5 mm once every 3 days for 30 days. Our study showed that a 0.5-cm burial depth and under 10- to 20-mm single-watering regimes resulted in highest seedling emergence percentage and rate of these four species. All emerged seedlings of Caragana korshinskii, Hedysarum laeve and Artemisia ordosica died under 2.5, 5 and 7.5 mm of watering, respectively, but seedling mortality was <50% when the single-watering regime was >10 mm. In the field, germination of the four species increased from the top of the dune to the middle of the leeward side and then to the bottom. Based on precipitation pattern in the Mu Us sandy land, our study indicates that 0.5-cm burial depth and a single-watering regime of >7.5 mm is the threshold condition for seedling emergence. [source] Simulated effects of herb competition on planted Quercus faginea seedlings in Mediterranean abandoned croplandAPPLIED VEGETATION SCIENCE, Issue 2 2003Benayas Rey Abstract. We tested simulated effects of herb competition on the performance of planted seedlings of Quercus faginea ssp. faginea in Mediterranean abandoned cropland. We produced three types of environment with respect to herb competition: absence of competition (AC), below-ground competition (BGC), and total competition (TC). We assessed the performance of Q. faginea seedlings in each treatment in five ways: (1) seedling mortality, (2) leaf length and total plant leaf area, (3) water potential, (4) total biomass and biomass allocation, and (5) non-structural carbohydrate storage in different plant organs. We also measured (6) soil moisture at different depths and (7) biomass production of herbs. The TC treatment reduced water availability more than the BGC treatment, in agreement with the most pronounced water stress in seedlings under TC conditions. BGC and TC treatments showed a high and similar seedling mortality, which was one order of magnitude higher than that in the AC treatment. Competition treatments affected glucose concentration in both shoots and roots, and followed the rank TC > BGC > AC. Q. faginea seedlings might compensate a lower water availability through glucose accumulation in leaves to reduce the osmotic potential. There was a maximum starch concentration in the BGC treatment that hints that a moderate resource limitation would limit tissue growth but not carbon assimilation. We conclude that the negative effects of herbs on Q. faginea seedlings are mostly a result of competition for water, and that this competition is noticeable since the earliest stages of the establishment. Complete weed removal is a technique that would strongly improve seedling survivorship. [source] Lolium multiflorum density responses under ozone and herbicide stressAUSTRAL ECOLOGY, Issue 8 2009M. ALEJANDRA MARTÍNEZ-GHERSA Abstract Adaptations to overcrowding of individual plants result in density dependant control of growth and development. There is little information on how anthropogenic stresses modify these responses. We investigated whether combinations of diclofop-methyl herbicide and tropospheric ozone alter the pattern of expected growth compensation with density changes resulting from intraspecific competition in Lolium multiforum Lam (Poacea) plants. Individual plant vegetative parameters and total seed production were assessed for plants growing under various densities and different herbicide rates and ozone treatments. The stressors differently changed the frequency distribution for average individual plant weight resulting from increasing densities. Only herbicide affected seedling mortality. Plants were able to compensate during grain filling maintaining similar seed production , density relationships in all treatments. Our findings contribute to the understanding of the impact of stress factors on the demographic changes in plant populations. Important ecological implications arise: (i) contrasting responses to ozone and herbicide, alone and in combination of individual plants resulted in different biomass , density relationships; (ii) stress effects on plant populations could not be predicted from individual responses; and (iii) changes in competitive outcome by single or combined stress factors may alter the expected genotype frequency in a crowded population with few dominant individuals. [source] Edge Effects and Seedling Bank Depletion: The Role Played by the Early Successional Palm Attalea oleifera (Arecaceae) in the Atlantic ForestBIOTROPICA, Issue 2 2010Antônio Venceslau Aguiar ABSTRACT In this study, we examined the impacts of Attalea oleifera on the structure of seedling bank and discuss potential mechanisms of palm influence. Seed rain, seedling bank, and palm leaf fall were assessed beneath the canopy and in the vicinity of 16 adult palms across the edges of a large fragment (3500 ha) of the Atlantic forest. Moreover, we examined A. oleifera impacts on seed germination and seedling mortality by experimentally submitting seeds and seedlings to prolonged palm-leaf covering. As expected, seedling bank beneath the adults exhibited reduced abundance and species richness at local and habitat scale. Small to large seeds (3.1,30 mm) were underrepresented in the seed rain below adults palms, while experimental leaf covering drastically reduced both seed germination and seedling survivorship. A. oleifera leaf fall occurred over the whole year (3.6±2.7 leaves/individual/yr), which resulted in deep leaf litter mounds (10.7±9.2 cm). Finally, adult palm density (21.6±11.9 individuals/ha) correlated negatively with seedling density across Attalea clusters. Our results suggest that A. oleifera exerts negative effects on the seedling bank by reducing seedling abundance and richness as a consequence of two complementary mechanisms: impoverished and size-biased seed rain plus reduced seed germination and increased seedling mortality due to prolonged covering by fallen leaves. Abstract in Portuguese is available at http://www.blackwell-synergy.com/loi/btp [source] Seed Dispersal of a High Quality Fruit by Specialized Frugivores: High Quality Dispersal?,BIOTROPICA, Issue 2 2000Daniel G. Wenny ABSTRACT Dispersal quality, as estimated by the cumulative effects of dispersal, germination, seed predation, and seedling survival, was examined for Beilschmiedia pendula (Lauraceae) in Monteverde, Costa Rica. I determined the pattern of dispersal by finding seeds deposited by birds, protected the seeds from seed predators with cages to assess germination and seedling survival, and examined seed predation rates with marked seeds. Seed predation, germination, and seedling survival were compared between seeds naturally dispersed by birds and seeds placed at randomly located sites. Approximately 70 percent of seeds dispersed by birds (N= 244) were deposited <10 m from crown edges of fruiting B. pendula trees, although some seeds were dispersed at least 70 m away. Larger seeds were more likely to be dispersed under or close to the parent trees, and larger seeds produced larger seedlings. Seed size was not correlated directly with seedling survival, but larger seedlings at three months were most likely to survive one year. Seed predation by mammals and insects and seedling mortality due to fungal pathogens were concentrated beneath the crowns of parent trees. Seedlings and saplings were more abundant beneath fruiting B. pendula trees, but individuals farther away were taller on average. Thus, dispersal is beneficial for B. pendula, but such benefits appear most pronounced at a small spatial scale; seeds dispersed >30 m from the crown edges actually had a lower probability of survival than those dispersed 10,20 m. Only 10 percent of B. pendula. seeds received high-quality dispersal in terms of landing in the zone with the highest per seed probability of seedling survival 10,20 m from parental crowns. RESUMEN La calidad de dispersión, estimado del efecto acurnulativo de dispersión, germinación, predación de semillas, y sobrevivencia de plantulas fue examinada por Beikcbmiedia pendula (Lauracea) en Monteverde, Costa Rica. Determinté el partén de disperstón, encontrando semillas defecadas o regurgitadas por aves, protegi semillas de predatores con jaulas para determinar germinación y sobrevivencia de plantulas, y examiné la proporción de predación de semillas con semillas marcadas. Predación de semillas, germinación y sobrevivencia de plantulas fueron comparadas con semillas dispersadas naturalmente por aves y con semillas localizadas en lugares al azar. Aproximadamente 70 porcento de las semillas dispersadas por aves (N = 244) fueron depositadas cerca de 10 mdel horde de la corona de árboles en fruto de B. pendula, aunque algunas semillas fueron dispersadas hasta 70 m mas lejos. Semillas grandes tuvieron la tendencia de ser dispersadas debajo o cerca del Brbol parental, y semillas grandes produjeron plantulas grandes. El tamaño de la semilla no estaba correlacionada directamente con sobrevivencia de plantulas, pero plantulas grandes a 3 mesa tuvieron la tendencia de sobrevivir. Predación de semillas por los roedores y insectos, y mortalitad de plantulas por hongos patogtnicos fueron lo mas comun debajo de la corona de los árboles parentales. Plantulas y arbolillos fueron mós abundantes debajo de drboles en fruto de B. pendula, pero individuos distantes fueron en promedio más altos. Dispersión es favorable para B. pendula, pero estos beneficios aparentan ser más ptonunciados a una escala espacial menot; semillas dispersadas más de 30 m del horde de la corona en realidad tienen una probabilidad menor de sobrevivencia que las que son dispersadas entre 10,20 m. Solamente 10 porcento de las seniillas de B. pendula recibieron despersión de calidad alta en terminos de aterrizar en una zona con la más alta probabilidad de sobrevivencia de plantulas entre 10,20 m de la corona parental. [source] | |||||||||||||