Cibele Cardoso de Castro

Floral biology and breeding system of Psychotria tenuinervis Muell. Arg. (Rubiaceae) in the Atlantic rain forest, SE Brazil

(Floral biology and breeding system oi Psychotria tenuinervis Muell. Arg. (Rubiaceae) in the Atlantic rain forest, SE Brazil). The aim of this study was to investigate pollination biology, floral morphometry, morph ratio and breeding system oiPsychotria tenuinervis in an area of Atlantic rain forest in southeastern Brazil. Pollination biology was studied based on focal observations and the breeding system was determined using controlled crosses; data on flower production and floral morphometry were compared between the two floral morphs. Flower production by the two floral morphs was similar, with flowers being reciprocally herkogamous, diurnal and pollinated at similar frequencies, mainly by medium-sized bees. Corolla length and diameter, as well as anther length, were similar between the floral morphs, whereas stigma lobes were larger in thrums. Psychotria tenuinervis is a preferentially self- and intramorph-incompatible, non-apomitic species, with isoplethic populations. At the study site, P. tenuinervis may be considered as a typical distylous species, with reciprocal herkogamous flowers that favour intermorph pollinations and legitimate matings.

Floral polymorphism in Chamaecrista flexuosa (Fabaceae-Caesalpinioideae): a possible case of atypical enantiostyly?

BACKGROUND AND AIMS Reciprocal herkogamy, including enantiostyly and heterostyly, involves reciprocity in the relative positions of the sexual elements within the flower. Such systems result in morphologically and, since pollen is deposited on and captured from different parts of the pollinator, functionally distinct floral forms. Deviations from the basic pattern may modify the functionality of these mechanisms. For heterostylous species, such deviations are generally related to environmental disturbances, pollination services and/or reduced numbers of one floral morph. Deviations for enantiostylous species have not yet been reported. This study aims to investigate enantiostyly in Chamaecrista flexuosa, in particular the presence of deviations from the standard form, in an area of coastal vegetation in north-east Brazil. METHODS Observations and investigations of floral biology, the reproductive system, pollinator behaviour, floral morphology and morphometry were performed. KEY RESULTS In C. flexuosa flowers, anthers of different size but similar function are grouped. The flowers were self-compatible and set fruits after every treatment, except in the spontaneous self-pollination experiment, thereby indicating their dependence on pollen vectors. The flowers were pollinated by bees, especially Xylocopa cearensis and X. grisencens. Pollen is deposited and captured from the ventral portion of the pollinators body. Variations in the spatial arrangement of floral elements allowed for the identification of floral morphs based on both morphological and functional criteria. Using morphological criteria, morphologically right (MR) and morphologically left (ML) floral morphs were identified. Three floral morphs were identified using functional criteria: functionally right (FR), functionally central (FC) and functionally left (FL). Combinations of morphologically and functionally defined morphs did not occur in equal proportions. There was a reduced frequency of the MR-FR combination. CONCLUSIONS The results indicate the occurrence of an atypical enantiostyly in C. flexuosa. This seems to improve reproductive success by increasing the efficiency of pollen deposition and capture.

Petal micromorphology and its relationship to pollination.

The characteristics of petal epidermal conical cells affect the quality of the signals perceived by various pollinators. This study aimed to identify variations in micromorphological characteristics of flower petals and their relationship to melittophily, ornithophily and chiropterophily pollination systems. The petals of 11 species were analysed using scanning electron microscopy and optical microscopy and the micromorphological traits were described, measured and compared using Tukeys test, PCA and cluster analysis. Unlike chiropterophily, all melittophilous and some ornithophilous species possessed adaxial epidermal conical cells. Cluster grouping separated chiropterophilous flowers from melittophilous and ornithophilous. PCA analysis showed that the two morphometric profile of conical cells was the attribute that most strongly influenced the grouping of species. When considering the data set of the three pollination systems, melittophilous and ornithophilous plants were more similar to each other than they were to chriopterophilous species. The distance between conical cell apices is an important parameter in interactions with pollinators. This study facilitated recognition of smoothing pollinator resource access through petal micromorphological characteristics. Further research regarding the biometry of micromorphological traits related to pollination is required.

Phenology of Spondias tuberosa Arruda (Anacardiaceae) under different landscape management regimes and a proposal for a rapid phenological diagnosis using local knowledge

BackgroundStudies aimed at investigating the influence of habitat change on species phenology. Studies that investigate peoples perceptions of the phenology of certain species still area few; yet this approach is important for effective decision-making for conservation. The aim of this study was to investigate the phenology of Spondias tuberosa Arruda (Anacardiaceae), a native species of economic and ecological importance in northeastern Brazil, in five landscape units (LUs) (Mountain, Mountain Base, Pasture, Cultivated Areas and Homegardens) of a Caatinga region in Altinho, Pernambuco, northeastern Brazil. These data could then be compared with local peoples perceptions of the species’ phenophases.MethodCollection of phenological data was carried out monthly from February 2007 to January 2009 and included activity, intensity and synchronization of reproductive and vegetative phenophases. Ethnobotanical data were gathered using a collaborative approach to access local people’s knowledge about the species’ phenological schedule.ResultsThere were no significant differences in the intensity of phenophases among LUs, and there was a correspondence between people’s perception of phenophases and the phenological data collected. The data show that the different management practices for LUs did not influence the phenology of the species.ConclusionThe main conclusion of this study is the use of traditional knowledge as interesting tool for rapid phenological diagnosis. However further studies need to be developed to test this tool in other environments and cultural contexts.

People and Natural Resources in the Caatinga

The interaction of people with the natural environment is ancient. Humans have great power to transform the natural environment and to interfere with the food chain and the processes that enable the renewal of populations of other species. The needs and demands for subsistence and economic growth convert natural systems to social-ecological systems. This chapter aims to highlight the findings of studies on the interactions of human populations with animal and plant resources in the Caatinga. In this type of ecosystem, seasonal and inter-annual variations in the rainfall pattern and the unpredictability of the total annual rainfall as well as the length of each season and the occurrence of interrupting events in the duration of each season in time and space have great influences on ecosystem functioning and the life dynamics of human populations. The collection of forest products and the hunting of wild animals of the Caatinga generate transformations in habitat conditions and often diversify the types of forest microhabitats. This ultimately affects not only the life cycle of resource use but also the dynamics of other species and over the medium- and long-term, the sustainability of human practices and the dynamics of the entire social-ecological system. Thus, we discuss the role of people in ecological processes and identify gaps that need to be filled for a change in perception and the integration of humans in ecological studies.

Enantiostylous types of Cassiinae species (Fabaceae‐Caesalpinioideae)

Species of the subtribe Cassiinae present a wide diversity of floral types. Until recently it was considered that this diversity did not extend to their reproductive mechanisms. However, studies have recorded some variations in the enantiostylous pattern in this plant group. This study aims to investigate the morphological and functional variations of enantiostyly in species of the subtribe Cassiinae. Additionally, it proposes the recognition of enantiostylous types (ET) based on pollen deposition and capture mode. Morphological data were collected in fresh and fixed (alcohol 70%) buds and flowers, and also using photos and rehydrated material from herbarium sheets, for a total of 59 species. The parameters used to establish the ETs were pollination type, nature of pollen deposition on the pollinator body, deposition type, number of petals involved in pollen deposition, and pollen pathway. Morpho-functional features allowed the recognition of seven enantiostylous types (Flexuosa, Cana, Macranthera, Martiana, Amiciella, Repens and Ramosa) that present several levels of complexity. The type Ramosa was the most common and the Cana type was the least common. The types Repens, Martiana and Flexuosa do not have reciprocal pollen deposition, thus species with these types may be considered atypical. The groups resulting from similarity analysis partially coincide with the clades proposed in phylogenetic studies of Cassiinae. The recognition of functional ETs is important for understanding the evolution of reproductive strategies of Cassiinae species, and indicates an interesting line of investigation of enantiostyly in other plant groups.

Biologia reprodutiva e flores de óleo em Cipura paludosa (Iridaceae)

Cipura paludosa is taxonomically placed in the Iridaceae family which is notable for the diversity of pollination systems, offering resources such as nectar, pollen and oil. The study was conducted within a fragment of Atlantic Forest in Recife, Pernambuco, to investigate the floral and reproductive biology of C. paludosa. The floral opening period, stigmatic receptivity, anther dehiscense, number of pollen grains, ovules per flower and floral morphology were evaluated; experiments regarding to the reproductive system and flower visitor observations were performed. Cipura paludosa is a herbaceous plant with melittophilous and self-compatible flowers, visited by Plebeia sp. and Augochlora thalia. The flower resources produced by C. paludosa were pollen and oil (produced in trichomal elaiophores). To ensure reproductive success Cipura paludosa benefits from pollination services since it produces only a few fruits spontaneously. The presence of bees not specialized in oil collecting may result in poor quality pollination services consequently reducing the species reproductive output.

Termite assemblages (Blattodea: Isoptera) in a habitat humidity gradient in the semiarid region of northeastern Brazil

We compared the termite assemblages of different ecosystems in a humidity gradient. Three areas were sampled: (i) a humid montane forest; (ii) a hillside forest where shaded coffee (Coffea arabica Linnaeus, 1753) is cultivated; (iii) a seasonally dry forest (Caatinga). Active collection protocols were employed in each area during the dry and rainy seasons. The species were grouped according to their habitats and feeding habits. A total of 45 termite species belonging to 20 genera and three families were encountered. The termite fauna of the Caatinga was as rich and abundant as that of the humid forest areas, but it was distinct from it in species composition. Most termite species encountered in the montane forest were also found in the agro-ecological site, but some species were only found in the latter. The termite fauna of the Caatinga varied seasonally the most, with significantly reduced abundance during the dry period. When species richness, abundance, and species composition were considered together the climatic seasons were not found to significantly affect the termite faunas in any of the study areas. The numbers of encounters per feeding group and per habitat exploited did not differ among the different areas, or during the different seasons. Even in adjacent areas, the humidity gradient, as well as the vegetational characteristics, are reflected in differences in the termite fauna. Agro-ecological regimes can be considered viable alternatives to traditional methods of cultivation as they largely conserve the biodiversity found in non-modified environments.

First report of predation on floral visitors by crab spiders on Croton selowii Baill. (Euphorbiaceae).

In the literature it has been extensively mentioned that crab spiders (Araneae: Thomisidae) prey on floral visitors of several plant species. Here we present observations of Croton selowii Baill. (Euphorbiaceae), a monoecious species harboring individuals of crab spiders in an area of coastal vegetation of Pernambuco state, Brazil. The species is visited by several invertebrate orders, and some of them were preyed upon by the spiders, mainly Diptera species. The spiders rubbed the forelimbs within the flowers, which may constitute a strategy to camouflage these structures. Croton selowii seems to represent a suitable foraging site for the spiders, because it has a generalist pollination system (thus being visited by a wide range of invertebrate species) and blooms in a period of low flower resource availability in the area.

Reproductive biology of the herkogamous vine Chiococca alba (L.) Hitchc. (Rubiaceae) in the Atlantic Rain Forest, SE Brazil

The family Rubiaceae comprises a wide spectrum of floral mechanisms and two of them seem to be common in certain groups, e.g., distyly in Rubioidae and styllar pollen in Ixoroidae. These mechanisms include herkogamy, which is interpreted as a strategy that avoids self-pollination. This is the first report on the reproductive biology of Chiococca alba, a species that is widely distributed in America. We studied floral biology and the mating system, which were evaluated through fruit set comparisons after controlled crosses (self- and cross-pollinations and test for apomixis), as well as through the evaluation of pollen tube growth resulting from these controlled crosses. Flowers of C. alba are herkogamous, cream, protandrous and lasted for two days. No measurable nectar was found, despite the presence of a nectary-like structure at the base of the corolla tube. Chiococca alba is a preferentially self-incompatible species, but self-pollination and apomixis also contribute to the natural fruit-set. Its reproductive strategy (herkogamy associated with protandry) is different from that expected for members of Chiococceae tribe (i.e., styllar pollen presentation).