Mutualistic interactions among free-living species in rupestrian grasslands

Abstract

Mutualisms such as animal pollination and seed dispersal, and protection of plants and insects by ants are ubiquitous in terrestrial ecosystems. Currently, mutualistic interactions among plants and animals are recognized for their paramount importance in biodiversity maintenance, especially in tropical ecosystems. In this chapter, we review the literature and present unpublished data on the ecology of mutualistic interactions among free-living species in Brazilian megadiverse montane Rupestrian Grasslands, the Campo Rupestre. We focus on interactions between plants and their pollinators and seed dispersers, and also interactions between ants, myrmecophilous plants and trophobiont insects. We provide basic information on mutualistic interactions, including data on natural history in addition to more advanced studies using network-based approaches. Only in the past decade mutualistic interactions have become intensively studied in Campo Rupestre, but information is still scattered and concentrated for a few localities. Pollination is an important process for reproduction of most plant species studied so far, with bees and hummingbirds acting as the main pollinators. Seemingly, animal pollination is more important than seed dispersal for gene flow across plant populations. Most vertebrate seed dispersal is carried out by non-specialized avian frugivorous, but also by short-distance seed dispersers such as ants and lizards. Moreover, ants are diversified and abundant group that seem to play a major role in these ecosystems, acting as secondary seed dispersers, as nectar thieves, and as bodyguards of plants and insects. We conclude this chapter by pointing out some gaps in our knowledge and proposing avenues for future research.