Mycorrhizas: Global Patterns and Trends

Abstract

Explaining the global distribution pattern and community dynamics of mycorrhizas in light of the established ecological paradigms assumes crucial importance, both in mycorrhizal studies and invasion ecology. What determines the global distribution of mycorrhizas? Does mycorrhizal diversity pattern follow the known latitudinal biodiversity gradient? How does distribution of mycorrhizas along different gradients and at different spatial scales influence distribution and diversity of host plant? Can mycorrhizas become invasive? These are some of the fundamental, yet completely unanswered, questions in mycorrhizal ecology. In fact, understanding the suite of environmental factors influencing the global distribution of AM fungi is fundamental to understanding and interpretation of the local dynamics of these fungi (Allen et al. 1995). Some recent global surveys of AM fungal taxa have indicated different distribution patterns, with some taxa showing a global range and others being limited to a few ecosystems only (Öpik et al. 2013). Some AM taxa are, however, rarely reported. In view of the rapid expansion and major breakthroughs in mycorrhizal research during recent years, novel insights have been obtained in understanding the community patterns and biogeography of mycorrhizal fungi. In fact, advances in mycorrhizal ecology, especially during the past decade, have turned our attention to even more novel dimensions, such as the possible consequences of mycorrhizal introduction and likelihood of these mutualists becoming invasive. Given the potential utility of fungal inoculations in agricultural, horticultural and ecological management, concerns have been expressed regarding the potential for negative ecological consequences of invasions by mycorrhizal fungi. In this chapter, an attempt is made to address these fundamental issues in light of handful studies conducted so far.