Tropical forest restoration: Role of soil biota-root symbioses (mycorrhizae and N-fixing bacteria)


Tropical forest restoration: Role of soil biota-root symbioses (mycorrhizae and N-fixing bacteria)

Tue, July 12, 10:30 - 12:30 hrs, Room: 304


Cecilia Prada, Lindsay McCulloch, Wenying Liao

Restoration efforts in the tropics often overlook the importance of belowground dynamics. However, studies have highlighted the key role of biota-root symbioses, such as mycorrhizae and symbiotic N-fixing bacteria, on tropical forest regeneration. This symposium aims to gather top researchers in the field to improve our understanding of tropical restoration.

Tropical forests are threatened by human land-use change, leading to consequences for climate, carbon sequestration, biodiversity conservation, and nutrient cycling. Active restoration efforts in the tropics have focused on planting native plant species to aid in the aboveground recovery of vegetation biomass and forest ecosystem services. However, there is growing evidence of the importance of belowground dynamics to the success of tropical forest restoration efforts. Specifically, recent studies have highlighted that the incorporation of soil biota-root symbioses, such as mycorrhizae and symbiotic N-fixing bacteria, can have important impacts on tropical forest regeneration. However, there are few studies evaluating the role that mycorrhizae and N-fixers play in tropical forest restoration and we lack conclusive empirical evidence on their effect for restoration in the field. For example, some studies demonstrate that mycorrhizae enhance plant nutrient uptake, resistance to pathogens, and improve soil physical characteristics. Similarly, other studies have shown that symbiotic N-fixing bacteria not only increase soil nitrogen but also increase carbon sequestration, benefiting degraded soils. Separately or together, mycorrhizae and N-fixers increase plant growth and biomass, improve soil organic matter — crucial characteristics for plant establishment. However, different types of mycorrhizal associations may have varied impacts on individual plant growth, with unclear influence on forest restoration. Similarly, variable interactions between individual nitrogen-fixing trees and neighboring plants may create null or even negative effects on stand-scale forest regrowth. Despite our growing understanding, there is still uncertainty in how interactions between plants and soil microbes will impact active restoration efforts. This symposium aims to bring together top researchers and practitioners in the field across a range of career stages and backgrounds to discuss the theoretical, conceptual, and applied aspects of mycorrhizae and N-fixing bacteriome in tropical forest restoration. The dual goals of this session will be to draw attention to the potential importance of soil microbes in tropical forest regeneration and to synthesize the critical early work on this topic. Talks in this session will comprise three complementary themes: 1) pan-tropical hypotheses and patterns for the role of soil microbial symbionts in forest regeneration, 2) results from empirical studies in both the Neotropics and Paleotropics, 3) examples of restoration efforts by practitioners that implemented plant-microbe symbioses. Together, these talks will provide important insight into the fundamental and applied components of plant-microbe symbioses as a critical, but currently underappreciated, aspect of tropical forest regeneration.

Afrotropical forest succession: from nitrogen to calcium limitation
Marijn Bauters and Viktor Van de Velde*

Microbial plant-soil feedbacks affect secondary succession of tropical rainforests
Anita Weissflog*, Bettina Engelbrecht, John R Healey and Lars Markesteijn

Integrating mycorrhizal associations with nutrient acquisition strategies in Southeast Asian dipterocarp forests
Ming Yang Lee*, Qian Yi Ho and Kelly Andersen

Advantages of being a N-fixing plant when restoring tropical dry forests
Laura Toro*, Jennifer Powers and Francisco Torres

The role of symbiotic nitrogen fixation and arbuscular mycorrhizae during secondary forest recovery in the Neotropics
Michelle Wong*, Nina Wurzburger, Christopher Neill, Divino Vicente Silvério, Paulo Brando, Kristin Saltonstall, Jefferson Hall, Roxanne Marino, Robert Howarth and Sarah Batterman