Report on the Ecological Significance of Seasonally Dry Wetlands and Their Contribution to Sustainable Development Goals

Introduction: The Role of Seasonally Dry Wetlands in Sustainable Development

A significant number of wetlands in Washington State are seasonally dry, appearing arid for much of the year. Despite their appearance, these ecosystems perform critical functions that align directly with several United Nations Sustainable Development Goals (SDGs). These wetlands are defined as areas where water is at or near the soil surface for a minimum of several weeks during the growing season, creating unique soil conditions and supporting specialized vegetation. Their functions, which persist even during dry phases, include water purification, flood mitigation, and habitat provision, making their protection essential for achieving global sustainability targets.

Contribution to Water and Climate-Related SDGs

The cyclical nature of Washington’s wetlands provides measurable benefits that support key environmental and community-focused SDGs.

SDG 6: Clean Water and Sanitation & SDG 14: Life Below Water

The seasonal drying and wetting cycle is fundamental to water quality improvement. This process facilitates the transition between anoxic (oxygen-free) and oxic (oxygen-rich) soil conditions, which is crucial for nutrient cycling and pollution reduction.

• Nitrogen Processing: Wetlands are highly effective at processing excess nitrogen, a common pollutant from agricultural runoff and combustion. This process mitigates the risk of eutrophication and harmful algal blooms in downstream water bodies, thereby protecting aquatic ecosystems and contributing to the goals of SDG 6 (Clean Water) and SDG 14 (Life Below Water).
• Sediment and Pollutant Filtration: As wetlands store water, they filter out sediments and other pollutants, further enhancing water quality for both human use and ecosystem health.

SDG 11: Sustainable Cities and Communities & SDG 13: Climate Action

Seasonally dry wetlands play a vital role in water resource management and climate resilience, directly supporting the objectives of making human settlements safe, resilient, and sustainable.

1. Flood and Erosion Control: During wet seasons, these wetlands absorb and store significant amounts of precipitation. This natural storage capacity slows runoff into streams and rivers, reducing the risk of flooding and erosion in nearby communities.
2. Drought Mitigation and Aquifer Recharge: The stored water helps recharge underground aquifers. This process is critical for maintaining streamflow during hot, dry periods, ensuring water availability and enhancing community resilience to climate change-induced droughts, a key target of SDG 13.

Contribution to Biodiversity and Terrestrial Ecosystems (SDG 15: Life on Land)

Seasonally dry wetlands provide unique habitats that are essential for the survival of specific species, directly contributing to the goal of halting biodiversity loss.

Specialized Habitats for Vulnerable Species

• Amphibian Refuges: These wetlands are critical breeding grounds for species such as the Pacific treefrog (Washington’s state amphibian). The seasonal absence of water eliminates fish and other permanent predators, creating a safe haven for tadpoles to mature. This specialized habitat supports the life cycles of amphibians that are integral to the region’s biodiversity.
• Invertebrate Life Cycles: Unique ecosystems like vernal pools, which dry completely, support invertebrates such as fairy shrimp. These species have adapted with dormant life stages that survive in dry soil until the return of water, showcasing a remarkable adaptation to these specific environmental conditions.

Case Study: Vernal Pools

Vernal pools represent a distinct type of seasonally dry wetland that exemplifies the principles of SDG 15. These pools hold water in the early growing season before drying out completely.

• They host unique plant and animal communities adapted to this wet-dry cycle.
• They serve as one of the most important habitats for waterfowl migrating through Washington in the spring.
• They are essential for the life cycles of specialized invertebrates, including fairy shrimp and seed shrimp.

Conclusion: Recognizing Wetland Value for Global Goals

The ecological services provided by seasonally dry wetlands in Washington are integral to achieving multiple Sustainable Development Goals, including those related to clean water (SDG 6), resilient communities (SDG 11), climate action (SDG 13), and biodiversity (SDG 14 and SDG 15). Recognizing the value of these ecosystems, even when they appear dry, is imperative for their conservation and for advancing a sustainable future.

Which SDGs are addressed or connected to the issues highlighted in the article?

SDG 6: Clean Water and Sanitation

• The article extensively discusses the role of wetlands in water management. It highlights their function in improving water quality by processing pollutants like nitrogen, storing floodwaters to prevent flooding and erosion, and recharging underground aquifers. These functions are central to ensuring the availability and sustainable management of water.

SDG 15: Life on Land

• The article emphasizes that wetlands, including seasonally dry ones, are vital habitats that provide a “safe haven” for various species. It mentions the Pacific treefrog, waterfowl, fairy shrimp, and seed shrimp, which rely on these specific ecosystems. This directly relates to protecting, restoring, and promoting the sustainable use of terrestrial and inland freshwater ecosystems and halting biodiversity loss.

What specific targets under those SDGs can be identified based on the article’s content?

SDG 6: Clean Water and Sanitation

1. Target 6.3: By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally.
   • The article explains that wetlands “improve water quality” and “help process excess nitrogen,” a common pollutant from fertilizers and combustion that can cause algae blooms. The natural chemical changes in wetland soils are described as helping to “reduce pollution.”
2. Target 6.6: By 2020, protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes.
   • The entire article is a call to recognize and value wetlands, which are explicitly named in this target. It describes their vital functions, such as storing floodwaters, recharging aquifers, and providing habitat, underscoring the importance of their protection.

SDG 15: Life on Land

1. Target 15.1: By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains and drylands, in line with obligations under international agreements.
   • The article’s main purpose is to highlight the importance of conserving wetlands (“inland freshwater ecosystems”) by detailing their essential services, such as water filtration, flood control, and providing unique habitats.
2. Target 15.5: Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity and, by 2020, protect and prevent the extinction of threatened species.
   • The article points out that seasonally dry wetlands are critical habitats for species like the Pacific treefrog, which uses them to avoid predators. It also mentions that vernal pools are “one of the most important habitats for waterfowl” and are essential for the life cycles of fairy shrimp and seed shrimp. Protecting these wetlands is crucial to preventing the degradation of these specialized habitats and protecting the biodiversity they support.

Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

For Target 6.3 (Improve water quality)

• The article implies that water quality can be measured by tracking the concentration of pollutants. It specifically mentions that “excess nitrogen not taken up by plants can cause algae blooms.” Therefore, an implied indicator is the level of nitrogen concentration in water bodies or the frequency and extent of algae blooms, which would decrease as wetland function improves.

For Target 6.6 and 15.1 (Protect and restore water-related ecosystems)

• Progress towards protecting wetlands can be measured by tracking their physical area. The official indicator for this target is Indicator 6.6.1/15.1.1: Change in the extent of water-related ecosystems over time. The article’s call to “recognize the wetlands in our landscape, even if they are dry” supports the idea of mapping and monitoring the total extent of these ecosystems to ensure they are not lost.

For Target 15.5 (Reduce habitat degradation and protect biodiversity)

• The article links the health of wetland habitats to the survival of specific species. The presence and population health of species like the Pacific treefrog, migratory waterfowl, and invertebrates like fairy shrimp can serve as bio-indicators. Monitoring the populations of these species, which are “specially adapted to wetlands that dry out,” would indicate the health and integrity of these unique habitats.

SDGs, Targets, and Indicators Analysis

Source: ecology.wa.gov