Impact of mycorrhizal associations on nutrient uptake and drought tolerance in native tree seedlings under climate change scenarios

Project Abstract

This study investigates how mycorrhizal associations influence nutrient uptake and drought tolerance in native tree seedlings under projected climate change scenarios, integrating ecological physiology, soil microbiology, and nutrient cycling dynamics. We hypothesize that ectomycorrhizal and arbuscular mycorrhizal fungi differentially enhance phosphorus and micronutrient acquisition, root hydraulic conductivity, and osmotic adjustment, thereby modulating seedling growth, water-use efficiency, and survival under elevated temperature and altered precipitation regimes. A factorial experimental design combines native tree species representing distinct mycorrhizal dependencies with controlled inoculum treatments (no inoculum, native AMF, native ECMF, and non-native inocula) across soil moisture gradients (well-watered, moderate drought, severe drought) and climate-simulated environments (ambient vs. elevated CO2, increased temperature). Growth metrics (height, biomass partitioning, leaf area), physiological traits (gas exchange, stomatal conductance, photosynthetic rate, chlorophyll fluorescence), and water relations (leaf water potential, osmolyte accumulation) will be measured alongside detailed nutrient analyses (total and extractable N and P, micronutrients, root ion flux). Microbial community structure and function will be characterized via amplicon sequencing of fungal ITS regions and functional gene inventories, enabling linkage between fungal assemblages and plant performance. At the plant level, we will quantify mycorrhizal colonization intensity, hyphal length density, and phosphorus use efficiency, while at the ecosystem scale we will model nutrient uptake dynamics and drought resilience indicators to project seedling persistence under 21st-century climate projections. The study will test the extent to which mycorrhizal networks mitigate drought-induced declines in photosynthesis through improved water uptake, altered root morphology, and enhanced nutrient translocation. We anticipate that AMF will predominantly improve phosphorus acquisition and drought tolerance in AMF-associated seedlings, whereas ECMF will more robustly support nitrogen use efficiency and structural root adaptations under stress, with synergistic effects when co-colonization occurs. Findings are expected to reveal threshold soil moisture limits for mycorrhizal benefits and to identify species-specific responses shaped by mycorrhizal type, soil fertility, and ambient CO2, thereby informing forest management strategies that leverage symbiotic associations to bolster seedling establishment and resilience in climate-impacted landscapes. The research will contribute to a mechanistic understanding of plant–microbe–environment feedbacks, offering predictive insights for nursery propagation, restoration planning, and biodiversity preservation under ongoing climate change.

Project Overview

What This Project Is About

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A plain-language overview of how fungi-related partners (mycorrhizae) help tree seedlings take up nutrients and survive drought, especially as climate changes. The project explores how these tiny partners support young trees to grow better when water is scarce or soils are nutrient-poor.

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The Problem It Addresses

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Young trees often struggle to get enough water and nutrients, which can slow forest regeneration and affect ecosystems. There is limited practical guidance on how mycorrhizal relationships influence seedling performance under drought and climate change.

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Objectives of the Project

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1. Describe what mycorrhizae are and how they interact with native tree seedlings.
2. Assess the effect of mycorrhizal inoculation on nutrient uptake in seedlings.
3. Evaluate seedling drought tolerance with and without mycorrhizal associations.
4. Identify practical indicators for seedling health under stressful water conditions.

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What You Will Do Step by Step

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1) Review simple background literature on mycorrhizae. 2) Grow native tree seedlings with or without mycorrhizal partners in controlled soil. 3) Measure basic nutrient levels and water-use indicators. 4) Subject plants to mild drought and observe responses. 5) Analyze differences between treatments using basic statistics. 6) Interpret results in plain terms and discuss implications for forestry and restoration.

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Expected Outcome

Clear conclusions on whether mycorrhizal associations improve nutrient uptake and drought tolerance in native seedlings, with simple guidance for restoration projects and future research directions.