Sociobiology 65(4): 612-620 (October, 2018) Special Issue DOI: 10.13102/Sociobiology.V65i4.3473
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Sociobiology 65(4): 612-620 (October, 2018) Special Issue DOI: 10.13102/sociobiology.v65i4.3473 Sociobiology An international journal on social insects Research article - Bees Seasonal Variation in Bee-Plant Interactions in an Inselberg in the Atlantic Forest in Southeastern Brazil MF Marques, MS Deprá, MC Gaglianone Programa de Pós-Graduação em Ecologia e Recursos Naturais, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Biociências e Biotecnologia, Laboratório de Ciências Ambientais, Campos dos Goytacazes, Rio de Janeiro, Brazil Article History Abstract Studies on bee-plant interactions are relevant to the understanding of temporal Edited by patterns in neotropical communities. In isolated habitats such as inselbergs little is Cândida Aguiar, UEFS, Brazil Received 10 May 2018 yet known about the temporal dynamics in the availability of floral resources and Initial acceptance 26 June 2018 interacting bee. In the present study, the objective is to verify the effect of seasonality Final acceptance 17 August 2018 on the bee-plant interaction in an Atlantic Forest inselberg in southeastern Brazil. Publication date 11 October 2018 The bees were sampled monthly in the dry (April/2008-September/2008) and wet seasons (October/2008-March/2009) using an entomological net. A total of 322 Keywords bees of 33 species were captured on flowers of 34 species of plants during the year. Floral Visitors, Seasonality, Semidecidual Forest, Ecological Networks. Bees richness was similar between seasons (22 species in the wet season and 21 in the dry season), but abundance was higher in the wet season (60% of individuals) Corresponding author and higher diversity occurred in the dry season. Augochloropsis sp1 were the most Marcelita França Marques abundant species and visited the largest number of plant species at each season. Universidade Estadual do Norte In the interaction network, plants with the highest degree were distinct between Fluminense Darcy Ribeiro Centro de Biociências e Biotecnologia the seasons. The number of possible interactions was higher in the dry season Laboratório de Ciências Ambientais compared to the wet season and connectance was similar; nestedness however Avenida Alberto Lamego nº 2000 varied between the seasons. The composition of plant and bees species was distinct Parque Califórnia, CEP 28013-602 between the seasons, as well as the interactions between them, mainly due to the Campos dos Goytacazes-RJ, Brasil. alteration in the composition of the plant species and the change in the choice of E-Mail: [email protected] the bees for the floral resources between the seasons. Introduction et al., 1999; Porembski & Barthlott, 2000; Silva, 2016). These ecosystems are subject to constant threats, including mineral The fragmentation and degradation of natural and semi- extraction and wide agricultural practices in the surrounding natural habitats and the consequent loss of plant species and areas (Silva, 2016). The forest formations in inselberg areas pollinators are recurrent concerns in the literature (Moreira can be determined by a complex system of gradients related to et al., 2015; Potts et al., 2016). Predicting how interactions altitude, soil depth, water availability, and climatic variation, between plants and pollinators change in the face of biotic and contributing to vegetation characterized by rupicolous abiotic factors is an important step in attempting to preserve communities and dry or savanna-like forests (Gröger & forest ecosystems (Sargent & Ackerly, 2008). Huber, 2007). Among the dry forests, the semi-deciduous Inselbergs are single or multiple rock outcrops occurring seasonal forest in southeastern Brazil is one of the most isolated in the surrounding flat landscape and they are considered threatened and fragmented ecosystems in the world, consisting among the priority areas for conservation (Porembski & Barthlott, of small scattered fragments (Santos et al., 2009; Pimenta et 2000). The different microhabitats resulting from a marked al., 2011). This fact raises the importance of studying the plant- microclimatic variation favor the establishment of different pollinator interactions in this ecosystem since it guarantees the species in these environments (Porembski et al., 1998), providing reproduction of plants and promotes their genetic diversity and refuges for rare or endemic plant and animal species (Santos also provides resources for animals (Rech et al., 2014). Open access journal: http://periodicos.uefs.br/ojs/index.php/sociobiology ISSN: 0361-6525 Sociobiology 65(4): 612-620 (October, 2018) Special Issue 613 These mutualistic interactions between bees and can be substituted between the seasons in the semidecidual plants may vary on different spatial and temporal scales, seasonal forest, resulting in the changing in the availability according to environmental conditions (such as temperature, of foraging resources that affects the bee-plant interactions. relative humidity and light intensity), and also to intrinsic characteristics of bees (activity and foraging periods) and Material and Methods plants biology (flowering period) (Olesen et al., 2008; Kleinert Study area et al., 2009; Burkle & Alarcón, 2011; Deprá & Gaglianone, 2018). In the studies of the composition and distribution of The samplings were carried out on semideciduous floral resources, the inselbergs constitute an excellent model seasonal forest area, Itaoca massif (21°48’ S 41°26’ W), a due to the geographic isolation and the endemism of species. rocky outcrop of 900 ha at 420 m a.s.l., in southeastern The environmental variables may be associated to the different Brazil. This inselberg is isolated amidst the surrounding patterns of occurrence and distribution of plant resources, flat landscape and flooded areas surrounded by pastures, especially in forests with seasonal climates such as inselbergs sugarcane plantations, and rock exploration activity. composed of deciduous or semi-deciduous forests (Morellato This area has a clear seasonal climate with low relative & Leitão-Filho, 1996; Nunes et al., 2005; Mauad et al., 2014). humidity comparing to other Atlantic Forest areas, and it The approach of ecological networks and their metrics is considered important for the floristic diversity of Rio de emerge as a contribution to the understanding of patterns Janeiro state (Pessanha et al., 2014) as a hotspot within the in the structures of interactions among species, the fragility Atlantic Forest (Murray-Smith et al., 2008). The climate of these interactions, the impact of the environmental and of the region is classified as Aw (sensu Köppen, 1948), anthropic effects, and the temporal and spatial variation of characterized by tropical hot and humid with a dry winter the species (Memmott et al., 2004; Silva et al., 2007; Deprá (April to September) and wet summer (October to March). & Gaglianone, 2018). This network approach contributes to In the studied period (2008 and 2009), the amplitude of the the planning required for the conservation and management abiotic values for the dry and wet seasons were: temperature of threatened environments (Biesmeijer et al., 2005). 21.6 to 26.6 °C and 24.6 to 28.5 °C, relative humidity 74 to Studies on the evaluation of the community structure 78% and 74 to 82%, and monthly rainfall 3.5 to 63.8 mm of bees and floral species in inselberg areas in Brazil have and 51.6 to 526.2 mm, respectively (Fig 1). Climatic data was been carried by Aguiar and Zanella (2005) and Batalha-Filho obtained from the weather station of Campos/RJ of National et al. (2007) in Caatinga phytophysiognomies in the state Meteorological Institute (INMET, 2017). of Bahia, Brazil. These authors approached the topic using traditional analytical tools of population and community Sampling studies. Studies on bee-plant interactions in a unique habitat such as the inselbergs, with rare and endemic species and Samplings of the floral visiting bees were carried out with seasonal vegetation that varies floral resources along in the dry (April/2008 to September/2008) and wet seasons the year, can bring relevant results for the understanding of (October/2008 to March/2009) in the semi-deciduous seasonal the temporal dynamics of plant-pollinators in the Atlantic forest vegetation, every 30 days, except in December when Forest. In addition they can provide knowledge to be used in sampling was not possible due to impassable roads caused by conservation programs of this ecosystem. intense rain. The sampling of bees was performed by a collector The present work aims to describe and analyze the using an entomological net, from 7 am to 4 pm. All flowering seasonal variation in interactions between plants and bees in an plants, mainly herbs and shrubs, were inspected for up to three Atlantic Forest inselberg. Our hypothesis is that the key plants minutes in search of their floral visitors in a trail called locally Fig 1. Climatic conditions between April 2008 and March 2009 at the Itaoca Inselberg in the Atlantic Forest in southeastern Brazil. Dry season: white color; Wet season: black color. Temperature: square; Relative Humidity: circles; Rainfall: bars. 614 MF Marques, MS Deprá, MC Gaglianone – Seasonal Variation in Bee-Plant Interactions “tower trail” with 3000 meters long. Arboreal plants were both plant and floral visitor species (Bph), and choices of sampled using extensive netting up to 5 m in height. floral visitor by plant species (Bo) between the seasons. This After capture, the bees were killed in flasks