Report on the Status of the Hudsonia-Silverling Riverwash Barren Plant Community and its Alignment with Sustainable Development Goals

Introduction: Assessing Threats to Terrestrial Ecosystems in New Hampshire

An investigation into the status of the hudsonia-silverling riverwash barren plant community along the Saco River reveals critical challenges to achieving Sustainable Development Goal 15 (Life on Land). This rare plant community, formed by the cohabitation of two already scarce species, the silverling and the hudsonia, represents a unique terrestrial ecosystem. Its survival is integral to local biodiversity, supporting specific relationships between flora, fauna, and fungi. Recent field research was initiated to verify the community’s existence, which was previously presumed to be extirpated from the state, highlighting a significant data gap in biodiversity monitoring.

Survey Findings and Decline in Biodiversity

A 2025 expedition led by New Hampshire state botanists Bill Nichols and Amy Lamb confirmed the continued, albeit precarious, existence of the community. The survey’s findings illustrate a dramatic decline, directly impacting targets within SDG 15 to halt biodiversity loss.

1. Initial Rediscovery: A surviving community was located at the Dahl Wildlife Sanctuary in North Conway, contrary to previous assumptions of its extinction in the region.
2. Historical Baseline: Records from 30-40 years prior documented 11 known sites for the community across New Hampshire and Maine.
3. Current Status: The recent comprehensive survey confirmed that only four of these sites remain viable.
4. Ecosystem Loss: The formerly largest site in New Hampshire has been functionally destroyed, with only a few non-viable clumps of hudsonia remaining. This represents a complete loss of a specific, localized ecosystem.

Primary Driver of Decline: Climate Change Impacts

The investigation identifies climate change as the principal factor in the ecosystem’s degradation, underscoring the urgent need for Sustainable Development Goal 13 (Climate Action). The increased frequency and intensity of extreme weather events have created untenable conditions for this specialized plant community.

• Increased Flood Intensity: While the community is adapted to a certain level of natural disturbance from flooding, recent high-precipitation events have exceeded the threshold for its survival.
• Habitat Destruction: Extreme flooding has physically washed away both the plant species and the specific sediment deposits they rely on for growth.
• Disruption of Natural Cycles: Studies indicate an increase in flood events during traditionally dry seasons, occurring when riverine species are not adapted to withstand high water levels. This directly threatens the stability required for such ecosystems to thrive.

Implications for Sustainable Development Goals

The decline of the hudsonia-silverling community serves as a critical indicator of broader environmental pressures and has direct implications for multiple SDGs.

• SDG 15 (Life on Land): The near-disappearance of this plant community is a tangible example of biodiversity loss. Its decline signifies a failure to protect and restore a unique terrestrial ecosystem, emphasizing the importance of conservation efforts to protect threatened species and their habitats.
• SDG 13 (Climate Action): The findings provide localized, empirical evidence of the destructive impact of climate change on sensitive ecosystems. This case reinforces the necessity of global and local action to mitigate climate change and adapt to its unavoidable consequences.
• SDG 11 (Sustainable Cities and Communities): Future research will investigate secondary pressures from human recreation and development. This aligns with the need for sustainable land-use planning to ensure that human activities do not further endanger fragile ecosystems adjacent to communities.

Conclusion and Future Directives

The survival of the hudsonia-silverling riverwash barren community is in a critical state. While its rediscovery offers a small window for conservation, its drastic decline highlights the severe impact of climate change on biodiversity. The intrinsic value of this ecosystem and the obligation to protect it align with the core principles of the Sustainable Development Goals.

Future actions will focus on achieving SDG 17 (Partnerships for the Goals) by fostering collaboration with other experts to quantify observations and develop data-driven conservation strategies. Protecting the remaining sites is an urgent priority for meeting national and international commitments to SDG 15 and preventing the irreversible loss of this unique component of the planet’s natural heritage.

SDGs Addressed in the Article

• SDG 15: Life on Land

  This goal is central to the article, which focuses on the conservation of terrestrial ecosystems and biodiversity. The entire narrative revolves around the decline of a rare plant community (the hudsonia-silverling riverwash barren) along the Saco River, the efforts of state botanists to track its existence, and the threats it faces. The article explicitly mentions the importance of these plants for supporting “the biodiversity along the river, creating specific relationships between animals, fungi and other organisms.”

• SDG 13: Climate Action

  The article directly links the disappearance of the plant community to climate change. It states, “climate change is likely behind the community’s disappearance,” and cites specific climate-related impacts such as “more frequent and more extreme” flood and precipitation events. This connects the local ecological issue to the broader global challenge of climate change and its consequences on natural habitats.

• SDG 6: Clean Water and Sanitation

  While not focused on water quality for human consumption, the article is deeply connected to the health of a water-related ecosystem. The habitat for the rare plants is the “gravel on the river’s bank,” and the ecosystem’s decline is caused by changes in the river’s flooding patterns. This directly relates to the protection and restoration of freshwater ecosystems like rivers.

Specific SDG Targets Identified

1. 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 is a case study of this target in action. It highlights the “silverling and the hudsonia, already rare plant species,” and a “rarer plant community” that state botanists feared was extinct. The decline from 11 known sites to only four demonstrates the degradation of natural habitats and the loss of biodiversity. The botanists’ work is an urgent action to understand the status of these threatened species to prevent their extinction.

2. Target 15.1: By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services…

   • The focus on the “hudsonia-silverling riverwash barren plant community” along the Saco River is a direct reference to an inland freshwater ecosystem. The article documents the failure to conserve this ecosystem, as a site that “used to be the largest… in New Hampshire” is now “all gone” due to flooding. The botanists’ research is the first step toward potential restoration and conservation efforts.

3. Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.

   • The article illustrates a lack of ecosystem resilience to climate-related hazards. It explains that while the plant community needs some flooding, “the level of disturbance associated with those high precipitation events was too much, it was untenable for this community.” The destruction of the largest site by “increased flood intensity” shows the devastating impact of these hazards, highlighting the need to strengthen the adaptive capacity of both natural and human systems.

4. Target 6.6: By 2020, protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes.

   • The entire story is set within a water-related ecosystem: the banks of the Saco River. The article documents the degradation of this specific ecosystem, noting the disappearance of the plant community due to changes in the river’s flooding patterns. The botanists’ hope “of preserving what’s left” aligns with the goal of protecting and restoring such ecosystems.

Indicators Mentioned or Implied

1. Indicator for Habitat/Species Decline (related to Target 15.5)

   • The article provides a clear, quantifiable indicator of decline. It states that historical records from 30-40 years ago showed “11 known sites,” but now, the botanists have confirmed that “only four sites exist.” This change in the number of known locations for a specific plant community serves as a direct measure of habitat loss and the threatened status of the species.

2. Indicator for Ecosystem Health/Extent (related to Target 6.6 and 15.1)

   • The article implies an indicator based on the size and viability of the ecosystem. At one former site, the botanists found only “a few clumps of hudsonia in a small patch which didn’t even meet the minimum standards to be classified as that community type.” This suggests a qualitative and quantitative assessment (size of the patch, density of plants) is used to measure the extent and health of the ecosystem.

3. Indicator for Climate Hazard Frequency/Intensity (related to Target 13.1)

   • The article points to an indicator used by scientists to explain the ecosystem’s collapse. It mentions that “flood and precipitation events have become more frequent and more extreme” and that “rivers are now seeing more flood events during their dry seasons.” This frequency and intensity of climate-related natural disasters is the specific indicator of the changing climate’s impact on the region.

SDGs, Targets, and Indicators Analysis

Source: nhpr.org