The Role of Biodiversity: Drivers of stability of freshwater wetlands 2.0

The systematic review by Song et al. (2024) focuses on the critical, yet often threatened, role of biodiversity in maintaining the functional stability of freshwater wetlands (FWs).

The key insights from this paper are centered on identifying the drivers of stability, the importance of specific biodiversity components, and the mechanisms through which human activities cause degradation.

🔑 Key Insights of the Systematic Review (Song et al., 2024)

1. The Crucial Role of Biodiversity in Functional Stability

The review confirms the fundamental ecological principle that high biodiversity enhances the stability of wetland functions.

• Mechanisms of Stability: Biodiversity achieves this stability primarily through two mechanisms:

  • Complementary Effects: Rich diversity allows different species to fully utilize resources (water, nutrients, sunlight) by occupying various ecological niches. This complementary use reduces competitive pressure and increases the overall efficiency and productivity of the wetland.

  • Disturbance Resistance: High biodiversity improves the stability and disturbance resistance of food chains by building complex food web structures, which helps mitigate the effects of external disturbances (like pollution or water level changes).

2. Focus on Plant and Microbial Diversity

The paper synthesizes research on the specific organisms that drive functional stability in FWs:

• Plant Diversity: Wetland plants are essential because they stabilize the sediment, regulate water flow, and influence nutrient cycling. The variety of plant functional types provides the foundation for the complementary effects noted above.

• Microbial Diversity: Microorganisms (bacteria, fungi, archaea) play an indispensable role in maintaining the essential functions of wetlands, such as water purification and nutrient cycling (especially nitrogen, phosphorus, and sulfur cycles). The health and stability of microbial communities are directly linked to the wetland's ability to process pollutants and maintain water quality.

3. Degradation Drivers and Impact Mechanisms

The review analyzes how external pressures compromise the biodiversity-stability relationship:

• Key Drivers of Degradation: The primary causes of wetland functional degradation are traced back to global population increases, economic development, and climate change. Specific human activities include:

  • Water level changes (often due to water competition with human uses).

  • Agricultural reclamation and land-use change.

  • Pollution and the use of herbicides.

• Impact on Stability: These disturbances alter the physical structure and chemical environment of the wetland, which in turn affects plant and microbial communities. This loss of diversity directly impairs the wetland's ability to maintain supporting and regulating services like nutrient cycling and water purification.

4. Importance for Conservation

The review emphasizes the practical application of BEF knowledge for effective management:

• Reference for Conservation: The paper aims to serve as an important reference for freshwater wetland conservation and the enhancement of their habitat function, particularly by integrating the understanding of plant and microbial roles into restoration planning.

• Future Research Focus: It advocates for future studies to illuminate the detailed impacts and mechanisms of habitat change on biodiversity, ensuring that conservation efforts are targeted and scientifically robust.

Reversing ecosystem degradation requires a comprehensive strategy that involves restoration (repairing damaged areas) and prevention (stopping ongoing damage). It must be executed across various levels, from local planting projects to global policy shifts.

The United Nations Decade on Ecosystem Restoration (2021–2030) provides the current international framework for these efforts.