Reproductive phenology of two co‐occurring Neotropical mountain grasslands

Aim

Climate tends to explain phenological variations in tropical ecosystems. However, water availability and nutrient content in soil strongly affect plant communities, especially those on old, climatically buffered, infertile landscapes (OCBILs), and may impact these ecosystems’ plant reproductive phenology over time. Here, we compare the reproductive phenology of sandy and stony tropical grasslands, two co‐occurring herbaceous communities of the campo rupestreOCBILs. We asked whether flowering, fruiting and dispersal are seasonal in both grasslands, and whether these phenophases differ due to variations in soil properties. We also asked whether the phenological strategies and the number of flowers and fruits differ between these two grasslands as soil conditions vary.

Location

Serra do Cipó, Minas Gerais, Brazil.

Methods

The phenology of herbaceous species of sandy and stony grasslands was monitored monthly over two consecutive years.

Results

Plants on sandy and stony grasslands flowered and fruited throughout the year. We did not find a distinct seasonal pattern at the community level of either studied grassland. However, flowering, fruiting and seed dissemination occurred in stony grasslands mainly during the rainy season, while sandy grassland species flowered in both seasons and fruited and disseminated seed mainly during the dry season, as observed in other savanna vegetation types in the Cerrado. Flower and fruit production was higher in sandy grasslands than in stony grasslands, which may be linked to higher water retention in sandy grassland soils. In both communities, species of Cyperaceae, Eriocaulaceae and Xyridaceae contributed most to overall production, whereas Poaceae and Velloziaceae, two important families in campo rupestre, barely participated in the reproductive phenology during our 2‐yr survey.

Conclusions

Despite a strong seasonal climate, there was no reproductive seasonal pattern at the community level in campo rupestre. This first investigation of Neotropical grassland phenology indicates that the differences in soil content may constrain the grassland reproductive phenology and restrict reproduction of stony grassland species to the most favourable season. Further studies of grassland phenology are necessary to disentangle the relative importance of soil, climate and other triggers, especially fire.     

Reproductive limits of a late-flowering high-mountain Mediterranean plant along an elevational climate gradient

Mountain plants are particularly sensitive to climate warming because snowmelt timing exerts a direct control on their reproduction. Current warming is leading to earlier snowmelt dates and longer snow-free periods. Our hypothesis is that high-mountain Mediterranean plants are not able to take advantage of a lengthened snow-free period because this leads to longer drought that truncates the growing season. However, reproductive timing may somewhat mitigate these negative effects through temporal shifts. We assessed the effects of flowering phenology on the reproductive success of Silene ciliata, a Mediterranean high-mountain plant, across an altitudinal gradient during two climatically contrasting years. The species showed a late-flowering pattern hampering the use of snowmelt water. Plant fitness was largely explained by the elapsed time from snowmelt to onset of flowering, suggesting a selective pressure towards early flowering caused by soil moisture depletion. The proportion of flowering plants decreased at the lowest population, especially in the drier year. Plants produced more flowers, fruits and seeds at the highest population and in the mild year. Our results indicate that water deficit in dry years could threaten the lowland populations of this mountainous species, while high-altitude environments are more stable over time.     

Temporal and sexual variation of leaf-produced pollinator-attracting odours in the dwarf palm

Information on intra-specific variation in pollinator-attracting floral traits provides clues to selective pressures imposed by pollinators. However, these traits also reflect constraints related to floral phenology or morphology. The specific weevil pollinator Derelomus chamaeropsis of the dioecious Mediterranean dwarf palm Chamaerops humilis is attracted by volatile compounds that leaves, and not flowers, release during anthesis. Production of these olfactory cues is thus probably not constrained by any other floral function. This provides the opportunity to study variation of a floral trait that is not produced by a floral organ. We studied volatile compounds emitted by leaves of 12 individual C. humilis over the whole flowering season. The quantity of volatile compounds emitted by leaves reached a maximum when plants required pollinator visits. The relationship between odour emission and floral phenology was slightly different between male and female plants, probably reflecting differences in the exact time at which females and males benefit from pollinator visitation. Male plants produced higher quantities of volatile compounds than females. Odour composition was highly variable among individuals but did not differ between male and female plants. In this system, female C. humilis are pollinated by deceit and pollinators should be selected to avoid visiting them. The absence of sexual difference in blend composition may thus prevent pollinators from discriminating between male and female plants.An erratum to this article can be found at     

Between-year variation in flowering and fruit set in frost-prone and frost-sheltered populations of dioecious Rubus chamaemorus

Summary The flowering and fruiting patterns of the dioecious perennial herb Rubus chamaemorus L. were studied in frost-prone (open) and frost-sheltered (Shaded) habitats in northern Sweden over 6 years. The number of ramets with flower buds, the proportion of flower buds that opened, and fruit set varied markedly between years. In the frost-prone populations, the occurrence or absence of detrimental frosts during the development of flowers and fruit could explain much of the variation, both in the proportion of flower buds that developed into flowers, and in fruit set. In the frost-sheltered populations, most female flowers that did not develop into fruit aborted without any signs of physical damage and before any ovules had begun to enlarge. Flower mortality caused by herbivores feeding on reproductive parts was commonly low, but reached values higher than 10% in one of the shaded populations. Hand-pollination increased the proportion of ovules producing seeds in the mature fruits by about 20%, and in one year also increased fruit set significantly in one population. Fruit-producing female ramets had a higher mortality and a lower probability of flowering in the subsequent year than male ramets and non-fruiting female ramets. In R. chamaemorus, the conditions for fruit maturation are highly unpredictable at the time of flower initiation. It is suggested that the apparent over-initiation of flower buds is advantageous, as it allows the plant to attain a high reproductive success in years favourable for flowering and fruit development.     

Reproductive biology ofPolyalthia littoralis (Annonaceae)

Flowering phenology of some annonaceous trees and reproductive biology ofPolyalthia littoralis (Annonaceae) were studied. The trees showed various types of flowering phenology within the family. Among them,P. littoralis had hermaphroditic and protogynous flowers, and exhibited continuous flowering throughout the year. Bagged flowers set fruits and seeds comparable to the control. The observations of meiotic stages and the results of castrated tests indicated no possibility of apomictic reproduction. The abscised anthers attached to torus by the extended spiral thickenings, and accomplished self-pollination. Outbreeding possibly occurs, but the following self-pollination guarantees seed set.     

Flowering phenology of invasive alien plant species compared with native species in three Mediterranean-type ecosystems

Background and Aims

Flowering phenology is a potentially important component of success of alien species, since elevated fecundity may enhance invasiveness. The flowering patterns of invasive alien plant species and related natives were studied in three regions with Mediterranean-type climate: California, Spain and South Africa''s Cape region.

Methods

A total of 227 invasive–native pairs were compared for seven character types across the regions, with each pair selected on the basis that they shared the same habitat type within a region, had a common growth form and pollination type, and belonged to the same family or genus.

Key Results

Invasive alien plant species have different patterns of flowering phenology from native species in the three regions. Whether the alien species flower earlier, later or at the same time as natives depends on the climatic regime in the native range of the aliens and the proportion of species in the invasive floras originating from different regions. Species invading at least two of the regions displayed the same flowering pattern, showing that flowering phenology is a conservative trait. Invasive species with native ranges in temperate climates flower earlier than natives, those from Mediterranean-type climates at the same time, and species from tropical climates flower later. In California, where the proportion of invaders from the Mediterranean Basin is high, the flowering pattern did not differ between invasive and native species, whereas in Spain the high proportion of tropical species results in a later flowering than natives, and in the Cape region early flowering than natives was the result of a high proportion of temperate invaders.

Conclusions

Observed patterns are due to the human-induced sympatry of species with different evolutionary histories whose flowering phenology evolved under different climatic regimes. The severity of the main abiotic filters imposed by the invaded regions (e.g. summer drought) has not been strong enough (yet) to shift the flowering pattern of invasive species to correspond with that of native relatives. It does, however, determine the length of the flowering season and the type of habitat invaded by summer-flowering aliens. Results suggest different implications for impacts at evolutionary time scales among the three regions.Key words: Biological invasions, flowering phenology, genetic inertia, Cape Floristic Region, California, Spain, Mediterranean-type ecosystems, water availability, climatic origin     

Landscape change alters reproductive phenology and sex expression in <Emphasis Type="Italic">Attalea</Emphasis> palms (Arecaceae) of southwestern Amazonia

As deforestation and land-use/land-cover change advance in tropical forest regions, an understanding of how plants adjust phenology and reproductive dynamics to altered landscapes can provide insights into plasticity, productivity, and population persistence. We compared the reproductive phenology, sex expression, and flower and fruit production of two monoecious Amazonian palms, Attalea phalerata and Attalea speciosa, in old-growth forest and as remnant trees growing in actively grazed pastures. Using 2 years of phenology data collected from natural populations near Vila Extrema, Rondônia, and eastern Acre, Brazil, we compared flowering and fruiting in the two habitats and tested for effects of palm height, crown size, and light availability on inflorescence and sex expression. Forest conversion to pasture stimulated greater overall flowering and fruiting in individual Attalea palms. As a population, remnant pasture palms continuously bore flowers and fruits year-round, while forest palms flowered seasonally in isolated peaks with consecutive months of inactivity. Crown size and greater light exposure affected flowering and fruiting dynamics in A. phalerata and A. speciosa, respectively, and increased light availability shifted A. speciosa sex expression towards greater female investment, primarily through regulation of sex determination and bud abortion. Removal of tropical forest does not always lead to the downfall of remnant tree populations, and under favorable conditions, such as abandonment of cropland and pasture, higher levels of reproduction can facilitate recovery of future generations. Tree species with flexible sex expression may be particularly resilient in the face of land-use and land-cover change.     

Inter- and intra-generic differences in growth,reproduction, and fitness of nine herbaceous annual species grown in elevated CO2 environments

In assessing the capacity of plants to adapt to rapidly changing global climate, we must elucidate the impacts of elevated carbon dioxide on reproduction, fitness and evolution. We investigated how elevated CO₂ influenced reproduction and growth of plants exhibiting a range of floral morphologies, the implications of shifts in allocation for fitness in these species, and whether related taxa would show similar patterns of response. Three herbaceous, annual species each of the genera Polygonum, Ipomoea, and Cassia were grown under 350 or 700 ppm CO₂. Vegetative growth and reproductive output were measured non-destructively throughout the full life span, and vegetative biomass was quantified for a subsample of plants in a harvest at first flowering. Viability and germination studies of seed progeny were conducted to characterize fitness precisely. Early vegetative growth was often enhanced in high-CO₂ grown plants of Polygonum and Cassia (but not Ipomoea). However, early vegetative growth was not a strong predictor of subsequent reproduction. Phenology and production of floral buds, flowers, unripe and abscised fruits differed between CO₂ treatments, and genera differed in their reproductive and fitness responses to elevated CO₂. Polygonum and Cassia species showed accelerated, enhanced reproduction, while Ipomoea species generally declined in reproductive output in elevated CO₂. Seed quality and fitness (in terms of viability and percentage germination) were not always directly correlated with quantity produced, indicating that output alone may not reliably indicate fitness or evolutionary potential. Species within genera typically responded more consistently to CO₂ than unrelated species. Cluster analyses were performed separately on suites of vegetative and reproductive characters. Some species assorted within genera when these reproductive responses were considered, but vegetative responses did not reflect taxonomic affinity in these plants. Congeners may respond similarly in terms of reproductive output under global change, but fitness and prognoses of population persistence and evolutionary performance can be inferred only rarely from examination of vegetative characters alone.     

Reproductive ecology of Cneorum tricoccon L. (Cneoraceae) in the Balearic Islands

This paper examines some aspects of the reproductive biology of Cneorum tricoccon L. (Cneoraceae), a Mediterranean relict shrub which evolved under tropical conditions during the Tertiary. The breeding system, the flowering and fruiting phenology, and the variability in fecundity within and among populations of this plant were examined in the Balearic Islands. The plant is andromonoecious, and pollen from male flowers appeared to be more fertile than pollen from hermaphrodite flowers. There was no limitation of pollen, and xenogamous crosses produced more fruit than geitonogamous ones. The efficiency of male flowers suggests that their use increases plant fitness, thus maintaining such a breeding system. Flowering time is unusual compared with other species in the habitat; there is synchrony among individuals, and flowers are produced almost continuously from November through June. Floral sex ratio (number of hermaphrodite flowers: total number of flowers) varied greatly both through the flowering season and between years and was not consistent through time, suggesting that sex expression may be determined more by factors such as resource status of the plant than by genetic factors. Fully developed fruits are observed from December to July. Fecundity varied among individuals depending upon plant size and was consistent during the three years of the study (1992–1994). Fruit crop also differed strongly among sites. The greatest, most vigorous and thus most fecund plants are found in some populations of Mallorca island, especially at high altitudes. In other Balearic islands with low altitudes (<200 m), such as Cabrera, individuals are always short, less leafy and less fecund.     

Phenology of temperate trees in tropical climates

Several North American broad-leaved tree species range from the northern United States at 47°N to moist tropical montane forests in Mexico and Central America at 15–20°N. Along this gradient the average minimum temperatures of the coldest month (T _Jan), which characterize annual variation in temperature, increase from –10 to 12°C and tree phenology changes from deciduous to leaf-exchanging or evergreen in the southern range with a year-long growing season. Between 30 and 45°N, the time of bud break is highly correlated with T _Jan and bud break can be reliably predicted for the week in which mean minimum temperature rises to 7°C. Temperature-dependent deciduous phenology—and hence the validity of temperature-driven phenology models—terminates in southern North America near 30°N, where T _Jan>7°C enables growth of tropical trees and cultivation of frost-sensitive citrus fruits. In tropical climates most temperate broad-leaved species exchange old for new leaves within a few weeks in January-February, i.e., their phenology becomes similar to that of tropical leaf-exchanging species. Leaf buds of the southern ecotypes of these temperate species are therefore not winter-dormant and have no chilling requirement. As in many tropical trees, bud break of Celtis, Quercus and Fagus growing in warm climates is induced in early spring by increasing daylength. In tropical climates vegetative phenology is determined mainly by leaf longevity, seasonal variation in water stress and day length. As water stress during the dry season varies widely with soil water storage, climate-driven models cannot predict tree phenology in the tropics and tropical tree phenology does not constitute a useful indicator of global warming.     

Reproductive Traits and Phenology of Plants in Tropical Dry Evergreen Forest on the Coromandel Coast of India

Qualitative reproductive traits of 84 plant species belonging to 41 families were studied in tropical dry evergreen forest on the Coromandel coast of India. Majority of species had rotate type, white-coloured, scented flowers, rewarding nectar and pollen and pollinated chiefly by bees. An association between floral traits and pollination spectrum is evident. Bee pollination was prevalent in pollination systems. Among the fruit types, drupe and berry were common in black and red colour respectively, and dispersed by zoochorous mode. Seeds of brown- and green-coloured dry fruits, without any reward were disseminated by wind and explosion. The reproductive phenophase of trees and lianas occurred mostly during the dry period from January to June, which receives rainfall of less than 50 mm a month. However, shrubs showed a peak in flowering and fruiting in wet period. Detailed phenological observations of 22 woody species revealed a seasonal and unimodal pattern in flowering. Although some species were in flower round the year, flowering activity was skewed towards the dry season. The fruiting activity showed a bimodal pattern, one peak in dry season and another in wet season. Many species displayed a temporal aggregation in flowering and fruiting. The significant relation was obtained between reproductive traits and phenology of plants in the tropical dry evergreen forest.     

An exception to Darwin's syndrome: floral position,protogyny, and insect visitation in Besseya bullii (Scrophulariaceae)

Darwin pointed out that plants with vertical inflorescences are likely to be outcrossed if the inflorescence is acropetalous (flowers from the bottom up), the flowers are protandrous (pollen is dispersed before stigmas are receptive), and pollinators move upward on the inflorescence. This syndrome is common in species pollinated by bees and flies, and very few exceptions are known. We investigated flowering phenology and pollinator behavior in Besseya bullii (Scrophulariaceae) and found that it did not fit Darwin's syndrome. The vertical inflorescence was acropetalous but the flowers were distinctly protogynous, so flowers with newly receptive stigmas appeared on the inflorescence above those with dehiscing anthers. A number of small insects visited B. bullii; bees in the family Halictidae (Augochlorella striata and Dialictus spp.) were most common. When insects moved between gender phases within inflorescences, they moved up more often than down (61% versus 39% of observations, respectively) but this difference was only marginally significant. Most visits were to male-phase flowers only, and this preference was more pronounced for pollen-foraging insects than for nectar-foraging insects. B. bullii was self-compatible, so its flowering characteristics potentially could result in considerable self-pollination. However, an average of 38% of the lowermost flowers opened before any pollen was available on the same inflorescence; these solo females had a high probability of outcrossing (though fruit set was relatively low in the bottom portion of the inflorescence). Upper flowers may also be outcrossed because downward insect movement was not uncommon. Therefore protogyny in B. bullii may not necessarily lead to more selfing than would protandry.     

Reproductive phenology of two Mimusops species in relation to climate,tree diameter and canopy position in Benin (West Africa)

Assessing species phenology provides useful understanding about their autecology, to contribute to management strategies. We monitored reproductive phenology of Mimusops andongensis and Mimusops kummel, and its relationship with climate, tree diameter and canopy position. We sampled trees in six diameter classes and noted their canopy position. For both species flowering began in the dry season through to the rainy season, but peaked in the dry season, whilst fruiting occurred in the rainy season and peaked during the most humid period. Flowering was positively correlated with temperature. Conversely, fruiting was negatively correlated with temperature and positively with rainfall, only in the Guineo‐Sudanian zone. For M. andongensis, flowering and fruiting prevalences were positively linked to stem diameter, while only flowering was significantly related to canopy position. For M. kummel, the relationship with stem diameter was significant for flowering prevalence only and in the Guineo‐Sudanian zone. Results suggest that phylogenetic membership is an important factor restricting Mimusops species phenology. Flowering and fruiting of both species are influenced by climate, and consequently climate change might shift their phenological patterns. Long‐term investigations, considering flowering and fruiting abortion, will help to better understand the species phenology and perhaps predict demographic dynamics.     

Selection on flowering time in Mediterranean high-mountain plants under global warming

Under climate warming, plants will undergo novel selective pressures to adjust reproductive timing. Adjustment between reproductive phenology and environment is expected to be higher in arctic and alpine habitats because the growing season is considerably short. As early- and late-flowering species reproduce under very different environmental conditions, selective pressures on flowering phenology and potential effects of climate change are likely to differ between them. However, there is no agreement on the magnitude of the benefits and costs of early- vs. late-flowering species under a global warming scenario. In spite of its relevance, phenotypic selection on flowering phenology has rarely been explored in alpine plants and never in Mediterranean high mountain species, where selective pressures are very different due to the summer drought imposed over the short growth season. We hypothesized that late-flowering plants in Mediterranean mountains should present stronger selective pressures towards early onset of reproduction than early-flowering species, because less water is available in the soil as growing season progresses. We performed selection analyses on flowering onset and duration in two high mountain species of contrasting phenology. Since phenotypic selection can be highly context-dependent, we studied several populations of each species for 2 years, covering their local altitudinal ranges and their different microhabitats. Surrogates of biotic selective agents, like fruitset for pollinators and flower and fruit loss for flower and seed predators, were included in the analysis. Differences between the early- and the late-flowering species were less than expected. A consistent negative correlational selection of flowering onset and duration was found affecting plant fitness, i.e., plants that bloomed earlier flowered for longer periods improving plant fitness. Nevertheless, the late-flowering species may experience higher risks under climate warming because in extremely warm and dry years the earlier season does not bring about a longer flowering duration due to summer drought.     

Reproducing under a warming climate: long winter flowering and extended flower longevity in the only Mediterranean and maritime Primula

Under the pressure of global warming, general expectations of species migration and evolution of adaptive traits should always be confirmed with species‐specific studies. Within this framework, some species can be used as study systems to predict possible consequences of global warming also on other relatives. Unlike its mountain congeneric, Primula palinuri Petagn. has endured all the climatic fluctuations since the Pleistocene, while surviving on Mediterranean coastal cliffs. The aim of this work was to investigate the possible evolution of reproductive biological and ecological traits in P. palinuri adaptation to a warmer environment. Data showed that flowering starts in mid‐winter; single flowers remain open for over a month, changing from pendulous to erect. The number of insects visiting flowers of P. palinuri increases during the flowering season, and pollination reduces flower longevity. Overall, the best pollen performances, in terms of viability and germinability, occur at winter temperatures, while pollinator activity prolongs flowering until spring. Moreover, extended longevity of single flowers optimises reproductive success. Both phenotypic plasticity and selective processes might have occurred in P. palinuri. However, we found that reproductive traits of the only Mediterranean Primula remain more associated with cold mountain habitats than warm coastal cliffs. Given the rapid trend of climate warming, migration and new adaptive processes in P. palinuri are unlikely. Response to past climate warming of P. palinuri provides useful indications for future scenarios in other Primula species.     

Non‐continuous reproductive phenology of animal‐dispersed species in young forest restoration plantings

Tree species that produce resources for fauna are recommended for forest restoration plantings to attract pollinators and seed dispersers; however, information regarding the flowering and fruiting of these species during early growth stages is scarce. We evaluated the reproductive phenology of animal‐dispersed tree species widely used in Atlantic Forest restoration. We marked 16 animal‐dispersed tree species in 3‐ to 8‐year‐old forest restoration plantings in Itu‐São Paulo, southeast Brazil. We noted the age of the first reproductive event, flowering and fruiting seasonality, percentage of trees that reached reproductive stages, and intensity of bud, flower, and fruit production for each species. Flowering and fruiting are seasonal for most species; only two, Cecropia pachystachya and Ficus guaranitica, exhibited continuous flowering and fruiting throughout the year; we also identified Schinus terebinthifolia and Dendropanax cuneatus fruiting in the dry season during resource scarcity. Therefore, we recommend all as framework species, that is, species that are animal‐dispersed with early flowering and fruiting potential, for forest restoration. Further, we recommend identifying and planting similar animal‐dispersed tree species that produce fruits constantly or in the dry season to maximize fauna resource availability throughout the year in tropical forest restoration plantings. Abstract in Portuguese is available with online material     

Plant interactions for pollinator visits: a test of the magnet species effect

Summary From 1985–1987, patterns of fruit and seed set were studied in a population of mayapple (Podophyllum peltatum), a clonal, self-incompatible herb found in deciduous woods in eastern North America. Mayapple flowers do not produce nectar, but depend on infrequent visits by nectar-seeking queen bumble bees for pollination. In all years female reproductive success in mayapple colonies was influenced by colony size (number of flowers), by the distance to neighbouring colonies and by proximity to lousewort plants (Pedicularis canadensis), a prolific nectar producer heavily visited by bumble bees. In all years fruit and seed set were greater in mayapple colonies <25 m from lousewort flowers than in matched colonies which were >50 m from lousewort. In 1985 and 1987 the frequency of queen bumble bee visits to flowers in colonies close to lousewort was about four times greater than to distant colonies. In 1986 I removed about 80% of lousewort flowers to test whether the enhanced fruit and seed set in mayapples close to lousewort was pollinator mediated. Mayapple colonies close to flowerless lousewort patches did not differ in fruit or seed set from matched colonies >50 m from lousewort. In contrast, mayapples close to flowering lousewort patches had greater fruit and seed set compared with distant colonies. Over all years, a larger proportion of mayapples close to flowering lousewort patches had enhanced fruit and seed set compared with colonies close to louseworts without flowers. Though rarely documented, this type of facilitative interaction between plants that are highly attractive to pollinators (magnet species), and co-flowering species that are rarely visited by pollinators, may be widespread in plant communities.     

Community-level flowering phenology and fruit set: Comparative study of 25 woody species in a secondary forest in Japan

We investigated the flowering phenology, pollinator visitation, and fruit set of 25 animal-pollinated woody species in a warm temperate secondary forest in Japan. Various species flowered sequentially from February to October. The principal pollinators were bumblebees, honey-bees, flies and/or beetles and birds; bumblebees and flies/beetles pollinated most trees. The duration of flowering was shorter for species that bloomed in the middle of the season than it was for species that bloomed earlier or later in the season. The timing of flowering was more synchronous within species that had a shorter flowering duration; this was also detected when phylogenetically independent contrasts were calculated. This could be important for the effective pollination of species with a short flowering duration because such species bloom sequentially over a short period of less than 1month around May. Fruit set was related not to pollinator type, sex expression, flowering sequence (in order of the date of peak flowering) or flowering duration, but to the relative abundance of the species in the forest. This correlation was detected for fly- and beetle-pollinated species but not for bumblebee-pollinated species. Thus, relatively rare plant species with opportunistic pollinators might experience limited fruit set because of insufficient pollinator services. Bagging experiments conducted on eight hermaphrodite species revealed that the fruit set of bagged flowers was nearly zero, lower than that of control flowers. These results indicate the importance of pollinators for successful reproduction and thus for the coexistence of plants in this secondary forest.     

Diet of the red howler monkey (Alouatta seniculus) in French Guiana

We report the feeding behavior and food preferences of a troop of red howler monkeys (Alouatta seniculus) over two annual cycles in primary tropical rain forest in French Guiana. The monkeys used 195 plant species from 47 families as food. Major food categories were young leaves (54%), mature fruits (21.5%), and flowers (12.6%). Other food categories included old leaves, immature fruits, termitarium soil, bark, and moss. The monkeys were less selective than other howler groups, since 19 plant species contributed 1% to their diet and accounted for only 35.7% of their total diet. The Sapotaceae was the most frequently eaten plant family and represented >10% of the total diet.     

Flowering phenology and reproductive success of native shrub Berberis darwinii Hook. along different light environments

Studies evaluating flowering phenology and reproductive success are necessary when we want to direct a domestication project in a species with a potential productive value. We studied flowering phenology and reproductive success of Berberis darwinii growing under different light conditions in its native distribution area in the Andean Patagonian forests of Argentina. We test the hypothesis that plants grown under conditions of high-light availability exhibit advanced phenology and higher reproductive success than those grown under conditions of lower light availability. Phenology and reproductive success were determined in three contrasting light conditions at two forest sites, which were, canopy, gap and forest edge. Plants did not bloom under the forest canopy. Flowering and fruiting period lengths were similar in both sites and light conditions of gap and forest edge during spring and summer. Although gap plants had more racemes per shoot, racemes of edge plants had more flowers, fruits and a higher proportion of flowers producing ripe fruit. We show that B. darwinii reproduction studied in the Andean Patagonian forests is conditioned by the canopy openness. Regarding reproductive success, edge plants invest less resources in flower production than gap plants to have similar fruit production.