Hardy plants and the role of mycorrhizal fungi

How Hardy Plants, Shrubs, and Trees Tackle Extreme Temperatures: The Role of Mycorrhizal Fungi in Plant Resilience

British gardens are often subject to unpredictable weather conditions, with extremes of both cold and hot temperatures. Hardy plants, shrubs, and trees have evolved over time to cope with these challenges, demonstrating incredible resilience in the face of adverse environmental conditions. A crucial ally in this resilience is mycorrhizal fungi, a fascinating symbiotic relationship that enhances the ability of plants to withstand extreme weather. In this article, we will explore how these hardy plants thrive in cold and hot weather and the remarkable ways mycorrhizal fungi support them on this journey.

Dealing with Extreme Cold:

The cold season in Britain can be quite harsh, with frost, ice, and chilling winds posing significant challenges to plant life. Hardy plants, shrubs, and trees possess several adaptations to survive and thrive during these conditions:

1. Dormancy: Many hardy plants enter a state of dormancy during winter, redirecting their energy inward and slowing down their metabolic processes. This protective measure helps them endure the cold and conserve vital resources.
2. Frost Tolerance: Some plants have developed adaptations to withstand freezing temperatures. They produce antifreeze proteins that prevent ice crystals from forming within their cells, reducing the risk of damage.
3. Thickened Cell Walls: In response to cold weather, certain plants fortify their cell walls with extra layers of lignin and cellulose. This reinforcement offers better protection against freezing temperatures and physical damage.
4. Evergreen Foliage: Evergreen plants retain their leaves throughout the year, providing a consistent source of energy even in winter. Their waxy coatings and needle-like leaves minimize water loss and protect them from frost.

Dealing with Extreme Heat

The British summer, while generally mild, can experience heatwaves, posing a different set of challenges to hardy plants, shrubs, and trees. To endure scorching temperatures, these plants employ a range of strategies:

1. Drought Resistance: Hardy plants often possess extensive root systems that allow them to tap into deeper water sources during prolonged dry periods. Some store water in their leaves, stems, or roots, ensuring survival during droughts.
2. Sun Tolerance: To deal with intense sunlight and prevent damage from harmful ultraviolet (UV) radiation, certain plants produce protective pigments, such as anthocyanins and carotenoids.
3. Reduced Transpiration: In hot weather, plants close their stomata to minimize water loss through transpiration. This adaptive response helps them conserve water while still allowing essential gas exchange.
4. Shedding Leaves: Deciduous trees shed their leaves in response to heat stress. This not only reduces water loss but also helps them conserve energy and focus on survival.

The Role of Mycorrhizal Fungi

Mycorrhizal fungi play a crucial role in supporting hardy plants, shrubs, and trees throughout all seasons, particularly in extreme temperatures. These remarkable fungi establish a mutualistic relationship with the plant roots, creating mycorrhizae. There are two primary types of mycorrhizal fungi found in British gardens:

1. Ectomycorrhizal Fungi: Commonly associated with trees like oak, beech, and pine, these fungi form a dense sheath around the root tips, extending their reach for nutrients. They enhance the plant’s ability to acquire phosphorus and other essential minerals from the soil, particularly in nutrient-poor conditions.
2. Arbuscular Mycorrhizal Fungi: These fungi form symbiotic structures called arbuscules within the plant root cells, aiding in the absorption of water and nitrogen from the soil. This relationship is particularly beneficial for a wide range of plants, including many shrubs and herbaceous species.

Mycorrhizal fungi support hardy plants in extreme temperatures by

• Enhancing Nutrient Uptake: Mycorrhizal networks extend far beyond the plant’s root zone, enabling them to access nutrients that would otherwise be out of reach. This becomes especially vital during cold weather when nutrient availability may be limited.
• Improving Water Availability: Mycorrhizal hyphae are incredibly efficient at absorbing water from the soil, assisting plants during dry, hot periods.
• Boosting Stress Tolerance: Mycorrhizal fungi release compounds that aid in stress tolerance, helping plants endure both cold and hot extremes.

In British gardens, hardy plants, shrubs, and trees exhibit remarkable resilience in the face of extreme temperatures, adapting to survive both cold and hot weather. Their ability to withstand these conditions is amplified by the mutualistic relationship with mycorrhizal fungi. These incredible organisms support plants by improving nutrient uptake, enhancing water availability, and boosting stress tolerance. As gardeners, understanding the intricate bond between hardy plants and mycorrhizal fungi empowers us to create thriving and resilient landscapes that flourish despite the challenges of unpredictable weather.