Araucaria Forest Research Articles

Edaphic filters as abiotic drivers of Myrtaceae assemblages in subtropical Araucaria Forest

This study investigated whether soil chemistry act as abiotic drivers of Myrtaceae assemblages, and also investigated the occurrence of indicator species. We first characterize the edaphic conditions of forest fragments occupied by Myrtaceae assemblages in Subtropical Araucaria Forest. Then, we investigated the association between soil chemistry and the structure of the assemblages. Finally, we verified which Myrtaceae species are chemical-edaphic bioindicators. We measured 2357 individuals belonging to 26 species from the Myrtaceae family. The Myrtaceae assemblages were predominantly composed by populations with aggregate spatial distribution pattern. This spatial behavior reflects their edaphic requirements because the soil conditions are heterogeneous even on a small scale, forming chemical-edaphic niche patches. Ecological dominance occurred in habitats characterized by restrictive environmental factors such as soils with high acidity and high availability of exchangeable aluminum. Acca sellowiana and Campomanesia xanthocarpa are indicator species of fertile soils, while Myrceugenia regnelliana is acid and low fertility soils indicative. In this study we show that soil acidity is an effective driver of Myrtaceae assemblages in Subtropical Araucaria Forest and the use of Myrtaceae indicators can enable policymakers and environmental inspectors to more easily enact conservation in Brazilian ecosystems.

Understanding bark thickness variations for Araucaria angustifolia in southern Brazil

This study aimed to understand bark thickness variations of Araucaria angustifolia (Bertol.) Kuntze trees growing in natural forest remnants in southern Brazil, and their relationship with quantitative and qualitative attributes. Bark thickness must be accurately estimated in order to determine timber volume stocks. This is an important variable for the sustainable management and conservation of araucaria forests. In spite of its importance and visibility, bark thickness variations have not been evaluated for this key species in southern Brazil. A total of 104 trees were selected, and their qualitative and quantitative attributes such as diameter at breast height (DBH), height (H), crown base height (CBH), crown length (CL), social position (SP), stoniness (ST), position on the relief (PR), vitality (VT) and branch arrangement (BA) were measured. The trees were categorized into two groups: red bark or gray bark. Regression analysis and artificial neural networks (ANN) were used for modelling bark thickness. The results indicate that: (1) bark thickness showed good correlation to DBH, with 0.76 as coefficient of determination (R2), 0.540 as Mean Absolute Error (MAE) and 22.4 root-mean-square error in percentage (RMSE%); (2) the trend changed according to bark colour, with significant differences for the intersection ( $$ \beta_{0} $$ – Pr > F: p = 0.0124) and slope ( $$ \beta_{1} $$ – Pr > F: p = 0.0126) of bark thickness curves between groups; (3) the highest correlation of bark thickness was found with: DBH (ρ = 0.88), H (ρ = 0.58), CBH (ρ = 0.46), SP (ρ = − 0.52), and BA (ρ = − 0.32); (4) modelling with ANN confirmed high adjustment (R2 = 0.99) and accuracy (RMSE% = 3.0) of the estimates. ANN is an efficient and robust technique for the modelling of various qualitative and quantitative attributes commonly used in forest mensuration. The effective use of ANN to estimate araucaria bark in natural forests reinforces its potential, besides the possibility of application for other forest species.

The phenology of Ligustrum lucidum (Oleaceae): climatic niche conservatism as an important driver of species invasion in Araucaria forest

Phenology expresses strategies related to resource use and can play an important role in the success of invasive plants. Araucaria forests are highly fragmented ecosystems that are increasingly impacted by invasive plants, such as Ligustrum lucidum (Oleaceae). The present study aimed to describe the phenological events of L. lucidum; identify the influence climate has on its phenophases; and compare reproductive phenophases between L. lucidum and that of Araucaria forest. The phenological study was conducted over the course of 24 months, with the intensity of each phenophase being evaluated by the Fournier Index. Ligustrum lucidum exhibited phenophases throughout the entire year in Araucaria forest, all of which exhibited a seasonal pattern except for leaf fall. The same pattern was observed for the species in its native area. Day length was the best predictor of the phenology of L. lucidum. The reproductive phenology of L. lucidum differed from that of Araucaria forest, especially with regard to fruiting. The influence of day length on the phenophases of L. lucidum seems to be part of a strategy for efficient resource acquisition and allocation. The competitive advantage of L. lucidum in Araucaria forest may be due to the maintenance of its climatic niche, which gives it a different reproductive phenology in comparison to native species. The present study shows how phenology can play an important role in the invasion process and highlights the importance of creating management strategies to avoid the spread of L. lucidum in the already threatened Araucaria forest ecosystem.

New record of Juliomys ossitenuis Costa, Pavan, Leite & Fagundes, 2007 (Rodentia, Sigmodontinae) in Santa Catarina state, southern Brazil

Juliomys ossitenuis Costa, Pavan, Leite and Fagundes, 2007 was previously known in Brazil from the Atlantic Forest of the Southeastern Region to the Dense Ombrophilous Forest and Araucaria Forest of the Southern Region. The new record from Chapecó, in Santa Catarina state, confirmed by morphological and cytogenetic analyses, extends its distribution about 300 km westwards. This is the westernmost record for the species, in a region characterized by the transition between deciduous and Araucaria forests.

Independent Evolutionary Responses to Quaternary Landscape and Climatic Changes of Two Codistributed Cactophilic Drosophila Species (Drosophila repleta group) in Open Areas of South America

AbstractEvolutionary processes related to climatic changes and ecological factors, such as microhabitat affinities and food specialization, can be important contributors to phylogeographic discordance between codistributed and related species. Here, we evaluate the evolutionary histories of two cactophilic and codistributed Drosophila species (Diptera: Drosophilidae) from South America, Drosophila antonietae and Drosophila meridionalis, where they use mainly Cereus hildmaniannus (Cactoideae: Cereeae) as host, using mitochondrial DNA sequences and species distribution modeling. The diversification of both species was estimated during the Pleistocene. For both species, the distribution of suitable areas through the Last Glacial period to the present showed a similar dynamic from Andes Valley through east and through the Paraná-Paraguay river basin to the Atlantic coastline. The current distribution of D. antonietae was influenced by demographic expansion and putative migration route from northwest to south and then to coast, with two genetic incipient groups with bidirectional genetic flow between them. For D. meridionalis, we suggested a migration route from south to north as well as to coast, with three genetic groups deeply structured with no evidence of demographic expansion. Our comparative results showed that the Quaternary paleoclimatic dynamic has had a similar role in both species (displacement of the high suitability areas) with similar routes but in different directions. Additionally, the Araucaria forest represents a putative biogeographic barrier for Drosophila species and also for host C. hildmaniannus. The phylogeographical differences between these species related to geographical distribution, genetic structure, and demographic history could be explained for differences to adaptation and plasticity to explore a new host.

Impact on soil and tree community of a threatened subtropical phytophysiognomy after a forest fire

Knowledge about the effects of fire on tree communities of Araucaria forests (AF) is scarce, although this physiognomy is among the most threatened ones in the entire Brazilian hotspot Atlantic Forest. With this study, we sought to answer the following questions: After three years of the fire, how has the soil of this forest remnant been recovering? Are fires in the AF able to change the structure, composition and species richness of tree community? The survey was carried out in a remnant of AF in an integral protected area in Brazil. Two areas were selected, one that has no fire history in the last 30 years (unburned) and another that burned recently. In each area 25 permanent plots of 20 × 10 m were allocated and all shrub-tree vegetation with DBH ≥ 4.8 cm was sampled. Our initial expectations were largely refuted, since we found no differences between the two areas in composition and richness of tree species and in most soil environmental variables, but only in the community structure. The majority of the dead individuals were concentrated in the smallest diameter classes (DBH < 9.8 cm). The only soil environmental variables that presented differences were pH and organic matter. Our study shows that the AF presents a significant resistance against forest fires, probably due to the evolutionary history of this physiognomy with fire. Nevertheless, several individuals died, so it is also important to highlight that preventive measures against fires are always relevant for conservation of this endangered physiognomy.

Good times, bad times: Resource pulses influence mammal diversity in meridional Brazilian highlands

Understanding spatiotemporal patterns of species distributions and their determinants is paramount in ecology. Here, we explore the relationship between the diversity of surviving mammals and two of the main alimentary resources (araucaria seeds and feijoa fruits) across the Araucaria Forest (FOM) in South America. First, we investigated the influence of landscape and environment on the species distribution and pulse of forest productivity. Then, we evaluated how these spatiotemporal pulses in resource availability influence the mammalian diversity. We analyzed the data via diversity descriptors, Morisita index and multiple regressions. Our findings highlighted that climate, tree density, and other environmental variables explained the pulses of productivity. Mammalian diversity of first-order consumers mammals—all those immediately feeding on seeds and fruits—was partially related to resource pulses. Our results revealed that the pulses of forest resources can influence mammal diversity over the years, including delayed responses and asynchronous oscillations. The integrity of vegetal elements of the FOM is key to maintain several mammal-mediated ecological processes. Maintaining the viability of tree populations, encouraging the sustainable use of non-timber resources, and promoting the conservation of the mammalian fauna, which is undergoing an unprecedented diversity crisis worldwide, can help to preserve the remaining ecological processes.

Morfometria de Araucaria angustifolia em diferentes altitudes no Sul do Brasil

Os índices morfométricos podem ser usados para subsidiar o entendimento da dinâmica de florestas naturais. Diante disso, objetivou-se descrever e avaliar as características morfométricas e dendrométricas de Araucaria angustifolia, como subsídio para compreensão da estrutura da floresta natural de araucária. Os dados foram mensurados em três municípios de Santa Catarina, considerando diferentes altitudes de ocorrência da espécie, com amostragem de 247 árvores, utilizando o método de Bitterlich, sendo medida a circunferência a 1,30 m do solo, altura total e de inserção de copa e raios de copa. As relações interdimensionais das árvores foram descritas por meio de índices morfométricos. O sítio 2 apresentou árvores de maior porte em relação ao diâmetro e área de copa. O sítio 3 apresentou a maior densidade de árvores (403 árvores ha-1), enquanto nos sítios 1 e 2 foram observadas 362 e 232 árvores ha-1, respectivamente. No sítio 3, a maior parte das árvores apresentou proporção de copa superior a 50% e formal de copa menor que 1, indicando árvores de copas mais estreitas e largas. O diâmetro da árvore apresentou correlação negativa e superior a 70% com o grau de esbeltez. Nos três sítios, o diâmetro apresentou correlação positiva com o diâmetro de copa.

Contributions to Proto-Jê Archaeology in the Southern Brazilian Highlands: Wood, Fire, and Landscape

The anthracological analyses of domestic and ceremonial contexts of proto-Jê archaeological sites in southern Brazil and Argentina have yielded data regarding landscape, fire technology, fuel economy, wood selection, and wood use from about 1200 to 250 years BP. The inhabitants of these sites built up the landscape that they occupied, actively constructing and experiencing their domestic and ceremonial places and possibly engaging in vegetation management practices. They gathered timber and firewood in the Araucaria Forest and in intensely modified areas covered by secondary vegetation. These practices likely included logging and gathering fallen deadwood. Our data indicate cultural selection of particular species. Inga sp., Jacaranda sp., and Araucaria angustifolia were probably selected because of the meaning of these woods in the cosmological dual system of proto-Jê societies. Bamboos and palm stems may have been used as kindling and for fire making. These results are an important contribution to our understanding of the proto-Jê occupation and the relationships that these groups maintained with their plant environment.

Fauna edáfica e suas relações com atributos químicos, físicos e microbiológicos em Floresta de Araucária

A permanente cobertura vegetal do solo, em Florestas de Araucária, contribui na conservação de sua biodiversidade edáfica. O objetivo deste trabalho foi avaliar o potencial da fauna edáfica e das variáveis ambientais explicativas (físico-químicas e microbiológicas do solo) na discriminação de florestas com araucária nativa e reflorestada. Avaliaram-se florestas com Araucaria angustifolia nativa (NF) e reflorestada (RF) em três regiões distintas no estado de São Paulo, representando três repetições. Em cada área, 15 amostras de solo foram coletadas para avaliação dos atributos físicos, químicos e microbiológicos e, nos mesmos pontos, procedeu-se às coletas da fauna utilizando-se o método de armadilhas de queda (Pitfall traps). A fauna do solo foi influenciada pela sazonalidade, apresentando maior abundância de indivíduos no verão. Os grupos Collembola, Formicidae e Coleoptera foram os mais abundantes, independentemente da época de amostragem e tipo de floresta. A Análise de Componentes Principais (ACP) e Análise Canônica Discriminante (ACD) claramente diferenciaram as áreas de araucárias. Na ACP, Hemiptera, Collembola e Diplopoda ficaram associados à RF no inverno, principalmente pelos maiores valores de matéria seca da serapilheira. Já em NF, foram os grupos Orthoptera, Hymenoptera, Araneae e Coleoptera, explicados pela melhor qualidade do solo e da serapilheira. No verão, ficaram associados à NF, os grupos Formicidae, Hemiptera, Orthoptera, Araneae, Coleoptera e Collembola, explicados pelos maiores valores de CBM, Ca, P, C-org, macroporosidade e atividade de desidrogenase. Na ACD, a abundância de grupos taxonômicos foi o atributo da fauna edáfica mais importante para a discriminação das florestas. Da mesma forma, a umidade do solo, teor de P no solo, porosidade total e teor de S na serapilheira contribuíram na discriminação das florestas. A semelhança entre as áreas, em relação aos grupos da fauna edáfica, indica que está ocorrendo uma estabilidade das áreas reflorestadas comparável às nativas.

Wild boar diet and its implications on agriculture and biodiversity in Brazilian forest–grassland ecoregions

We aimed to describe the composition of Sus scrofa diet in three Brazilian ecoregions characterized by a mosaic of forests and grasslands: Pampa, Araucaria Forest and Pantanal. We evaluated the possible risks that the species may represent for agriculture and conservation of biodiversity by analyzing the stomach content of 118 boars. We examined dietary patterns in each ecoregion using PCA (principal component analysis) and verified how diet varies according to individual attributes through redundancy analysis. We visualized the composition of macronutrients in a multidimensional space by means of RMT (right–angled mixture triangle). The wild boars presented a diverse diet, influenced by season, time of day, and local availability of resources. Cultivated grains and herbs were the most commonly consumed items, leading to a high carbohydrate intake. Damage to agriculture is potentially high given the large consumption of cultivated grains. Population growth and expansion may be limited by the low availability of protein in the ecoregions.

Correction to: Beta diversity as an indicator of priority areas for Myrtaceae assemblage conservation in Subtropical Araucaria Forest

In the original publication of the article, Table 1 was published with few errors and the Acknowledgement statement was inadvertently omitted. The corrected table and acknowledgement statement is provided in this Correction.

&lt;p&gt;&lt;strong&gt;Native Species of Sapotaceae Juss. in Paraná, Brazil&lt;/strong&gt;&lt;/p&gt;

Sapotaceae is a large family of angiosperms which has predominantly tree species, and worldwide distribution in subtropical and tropical regions. The Neotropics are one of the greatest centers of diversity of Sapotaceae, and in Brazil, the family comprises 12 genera and 234 species, of which 103 species are endemic. We present here a taxonomic treatment for the native species of Sapotaceae from the State of Paraná, with an identification key, descriptions, geographic distribution, phenology, illustrations, and current conservation status for all taxa. Twenty-two species were documented in Paraná, belonging to seven genera. The richest genus was Pouteria with 11 species, followed by Chrysophyllum with five species and Pradosia with two species. The genera Diploon, Ecclinusa, Manilkara, and Sideroxylon have only one species each. Pouteria guianensis and Pouteria ramiflora are new records for the state. The Atlantic Rain Forest is the richest vegetation type with six genera and 13 species, followed by the Seasonal Forest with three genera and nine species. The Araucaria Forest and Cerrado have two genera each, the former with three species and the latter with two species. Out of 22 species, one has been mentioned as endangered (EN), one is vulnerable (VU), one is near threatened (NT), nine are least concern (LC), and ten have not been evaluated (NE).

Beta diversity as an indicator of priority areas for Myrtaceae assemblage conservation in Subtropical Araucaria Forest

We can say that studies on diversity provide knowledgeable insights into which areas with different compositions will be initially preserved or those which require more attention for government supervision. Thus, we aim to evaluate the alpha, beta and gamma diversity of the Myrtaceae assemblages as a tool for indicating priority conservation areas. Herein we explore the different levels of diversity resulting from fragments distributed along an altitudinal gradient in the Subtropical Araucaria Forest in the Santa Catarina Plateau of the Brazilian Atlantic Forest. In sequence, the Jaccard index and ordination by Detrended Correspondence Analysis were used for the β-diversity analysis and floristic substitution. Finally, the spatial dependence was analyzed by the Mantel Test based on floristic and geographical distances. Our results show that Myrtaceae assemblages along the altitude gradient are characterized by heterogeneous floristic compositions (β-diversity 0.55–0.95 variation), in which fragments above 1300 m are physiognomically marked by a predominance of the Myrceugenia and Myrcia genera. Higher altitudinal amplitude was characterized as an indicator for selecting complementary fragments due to dependence on β-diversity (r = 0.6961; p-value = 0.001), aiming at greater conservation effectiveness. In this sense, the LGS and URI complementary fragments are strategic because they comprise high beta diversity, high richness, the presence of exclusive and endemic species, and are located in different river basins. Our results show beta diversity as an effective tool for indicating priority areas for the conservation of Myrtaceae assemblages in AF, however it is essential to consider the exclusive and endemic species together.

Reforestation processes, seasonality and soil characteristics influence arbuscular mycorrhizal fungi dynamics in Araucaria angustifolia forest

Intensive logging of Araucaria angustifolia has reduced the extension of Araucaria-dominated forests, causing a strong disturbance on the arbuscular mycorrhizal fungal (AMF) community. AMF play an important role in soil health and Araucaria forest establishment. However, the main drivers that determine the AMF dynamics in native and reforested areas remain poorly understood. Our study aimed at evaluating important factors (i.e. soil and litter characteristics, seasonality and reforestation practices) that can alter AMF community dynamics. We evaluated three regions of Araucaria forest located in São Paulo state, Brazil, including native and reforested sites. We evaluated the AMF community through soil spore extraction and identification and root colonization rates, and we compiled the data using correlations and diversity metrics (richness, abundance and diversity). Together, we recorded thirty-six AMF species during the two sampling periods at all sites. Genera with the greatest numbers of species were Glomus, Acaulospora, Scutellospora and Gigaspora. Soil macroporosity, K and P were always higher in native forests and moisture was higher in reforested sites. Root colonization, though also affected by seasonality, showed differential behavior for each region. In addition, AMF species abundance changed between native and reforested sites and according to the season. In region 1, when correlating AMF and physical–chemical soil and litter attributes in a Redundancy Analysis, there were few differences between native and reforested sites, both being very similar. However, native and reforested sites were clearly discriminated in the other two regions, mainly influenced by bulk density, litter N, pH, Al, total porosity and moisture. The main influence in AMF dynamics composition were litter physical and chemical attributes. However, the reforestation process and seasonality, especially in summer, contributed to discriminate regions, indicating the relevance of these aspects on the AMF profile, reinforcing the importance of integrating tools in the evaluation of the biological data set.

Myrtaceae from the Atlantic forest subtropical highlands of São Joaquim National Park (Santa Catarina, Brazil)

Abstract Studies that address the floristic composition of the Atlantic forest show that Myrtaceae is one of the richest families in number of tree species. In Southern Brazil, Myrtaceae is present mainly in forest formations, such as broadleaf rain forests and broadleaf cloud forests, mixed needle and broadleaf forests (Araucaria forests), and seasonal semi-deciduous forests. The objective of this study was to survey the Myrtaceae of the upper highlands of São Joaquim National Park, to contribute with the knowledge of its flora. Eight genera and 16 species of Myrtaceae were found: Acca sellowiana, Blepharocalyx salicifolius, Eugenia handroi, Myrceugenia (8 spp.): M. acutata, M. alpigena, M. euosma, M. miersiana, M. myrcioides, M. oxysepala, M. pilotantha, and M. regnelliana, Myrcia (2 spp.): M. aethusa and M. hartwegiana, Myrrhinium atropurpureum, Psidium salutare, and Siphoneugena reitzii. Descriptions, illustrations, an identification key and commentaries are presented. Other studies about Myrtaceae in highland areas of Southern Brazil present Myrceugenia as the richest genus in species, while other mentioned genera were not registered in SJNP upper highlands. The family’s richness patterns and diversity in a local and regional scale should be better investigated in the Atlantic Forest.

Fire history in Andean Araucaria–Nothofagus forests: coupled influences of past human land-use and climate on fire regimes in north-west Patagonia

Historical fire regimes are critical for understanding the potential effects of changing climate and human land-use on forest landscapes. Fire is a major disturbance process affecting the Andean Araucaria forest landscape in north-west Patagonia. The main goals of this study were to reconstruct the fire history of the Andean Araucaria–Nothofagus forests and to evaluate the coupled influences of climate and humans on fire regimes. Reconstructions of past fires indicated that the Araucaria forest landscape has been shaped by widespread, stand-replacing fires favoured by regional interannual climate variability related to major tropical and extratropical climate drivers in the southern hemisphere. Summer precipitation and streamflow reconstructions tended to be below average during fire years. Fire events were significantly related to positive phases of the Southern Annular Mode and to warm and dry summers following El Niño events. Although Euro-Chilean settlement (1883–1960) resulted in widespread burning, cattle ranching by Pehuenche Native Americans during the 18th and 19th centuries also appears to have changed the fire regime. In the context of climate change, two recent widespread wildfires (2002 and 2015) affecting Araucaria forests appear to be novel and an early indication of a climate change driven shift in fire regimes in north-west Patagonia.

Estrutura e composição da regeneração natural em um fragmento de Floresta Ombrófila Mista secundária

Estudos sobre regeneração natural e sua relação com a vegetação adulta são importantes para auxiliar no entendimento da dinâmica e sucessão de florestas secundárias. Para tanto, objetivou-se, neste estudo, realizar a caracterização florístico-estrutural e ecológica da comunidade regenerativa (DAP 5 cm) e sua similaridade com a adulta (DAP ≥ 5 cm) em um fragmento de Floresta com Araucária secundária. A regeneração foi amostrada em 24 parcelas em três classes de altura, sendo calculada a regeneração natural total (RNT). Foram amostrados 433 indivíduos, pertencentes a 66 espécies e 29 famílias botânicas, com destaque para Myrtaceae. A similaridade florística entre a regeneração e o estrato adulto foi alta (68,3%). A regeneração e o estrato adulto apresentaram alta diversidade e equitatividade e baixa dominância. Allophylus edulis (9,5%), Mollinedia clavigera (8,5%) e Myrciaria tenella (8,3%) foram as espécies de maior RNT. Porém, são típicas de sub-bosque e não apresentam importância no estrato adulto. As demais espécies destacadas na regeneração, entre elas espécies-chave como Ocotea porosa, devem seguir na estrutura futura da floresta. A maioria das espécies da regeneração são zoocóricas e heliófilas, porém a proporção de espécie de estágio tardio é maior na classe de maior tamanho, indicando que a floresta está em plena sucessão e avançando para seu clímax.

An approach to illustrate the naturalness of the Brazilian Araucaria forest

The concept of “naturalness” can be associated with conservation status, resilience, and biodiversity. Its most common definition relates to the degree to which a resource is similar to its original state. Hence, we developed a naturalness assessment method for the Brazilian Araucaria forest. We used data collected within 145 systematically distributed plots over an area of ∼56 000 km2. We selected five indicators to compose a unified naturalness index: (i) evidence of human activities inside the forest stand; (ii) abundance of naturalness-indicator species; (iii) standard deviation of diameter at breast height (Sdbh); (iv) species diversity of the understory–natural regeneration layer; and (v) forest stand landscape metrics. We then calculated the Euclidean distance between the vector generated from the indicators of an ordinary forest stand and the vector generated from a theoretical reference forest (TRF) with maximum naturalness. The reduced Sdbhreflected the stands’ diminished structural diversity as result of historical logging and other ongoing human activities. Most stands presented average naturalness compared with the TRF. Besides the lack of data on undisturbed forests to thoroughly evaluate the naturalness index, evidence suggested that it summarized relevant forest attributes to the extent that protected areas presented greater naturalness than nonprotected areas.

Solitary bee pollinators adjust pollen foraging to the unpredictable flower opening of a species of Petunia (Solanaceae)

AbstractDetails of the foraging patterns of solitary bees are much less well known than those of social species, and these patterns are often adjusted to exploit floral resources of one or only a few species. The specialized flower-visiting bees of Petunia are good models for investigating such foraging patterns. Here we analysed the floral biology and pollen presentation schedule of the endangered Petunia mantiqueirensis in mixed Araucaria forests of Serra da Mantiqueira, Brazil. Pollinators and their pollen foraging behaviour and food specialization were determined through analyses of scopa pollen loads. Flowers opened throughout the day and presented all their pollen resources within the first 30 min of anthesis, thus providing their pollen resources in an asynchronous fashion in one-flower packages throughout the day. Females of Pseudagapostemon fluminensis were the most frequent flower visitors, contacting stigmas in 96% of their visits, and were the unique effective pollinators of Petunia mantiqueirensis. These pollinators were responsible for the first three visits to 115 individually monitored flowers at any daylight hour, removing ~86% of a flower’s total pollen supply during the first visit. Although female bees harvest the majority of pollen resources of Petunia mantiqueirensis, analyses of scopa loads revealed that most of them also collect pollen from plants of other families while foraging for pollen in Petunia flowers.