Adapting Cultural Landscapes to Climate Change: How the Park Service Does It

From the National Park Service series "Climate Change Response Strategy and Cultural Landscapes".

Landscapes kept in good condition are better placed to adapt to a changing climate, and planning for climate change is now a standard part of preservation. As the National Park Service adapts its management, its preservation goals stay the same:

• preserve historic integrity;
• avoid impairment;
• protect cultural and natural resources;
• build resilience into the landscape;
• prepare for future conditions.

Compatible changes

When a historic landscape has to change to cope with new conditions, the change should match its character and keep its integrity. Managers often have to balance historic accuracy against what is practical to maintain.

Val-Kill, Eleanor Roosevelt National Historic Site. Around 1930, rows of native red pine (Pinus resinosa) were planted along Val-Kill Lane approaching Stone Cottage, and grew into a dense screen around the pool terrace and gardens. By the early 1960s their lower branches had thinned — probably from lack of pruning, poor drainage, more shade and red pine scale (Matsucoccus resinosae). The scale, most likely introduced to New York in 1939, has been devastating red pines at low elevations in the state's southeast, where hot, humid summers are becoming more common. Rather than replant red pines that would face the same threats, a substitute pine species would recreate the stand's historic character.

Red pines screening the pool terrace at Val-Kill in 1940. NPS.

Rapidan Camp, Shenandoah National Park. President Herbert Hoover and Lou Henry Hoover used this rustic retreat for rest, recreation and meetings during their White House years (1929–1933). Its dense native woods, which kept it cool in summer, were one of its defining features — the Hoovers fitted the camp's buildings around existing trees.

Hemlocks shading Rapidan Camp in the historic period (date unknown). NPS.

The hemlock woolly adelgid (Adelges tsugae), accidentally brought to the United States in the 1950s, is kept in check in its native Japan by predators and resistant trees; eastern American hemlocks have neither defence. In Shenandoah it has killed thousands of hemlocks, destroying shady streamside habitat and changing historic landscapes such as Rapidan Camp. Replanting hemlocks would need heavy pesticide use and would probably fail. One option is to let native yellow poplars grow into a canopy: deciduous, and different from the old hemlock glen, but quickly shady with little intervention — and perhaps a shelter for hemlocks again once the adelgid threat has passed.

Adelgid infestations look like tiny cotton balls at the base of hemlock needles. NPS / Wheeler.

Newer pest management also offers alternatives to removing trees: predator beetles (Laricobius nigrinus), the systemic insecticide imidacloprid and monitoring standards are helping keep historic hemlock forests healthy.

Working with natural systems

Cultural landscapes often include natural systems that are part of their character, and managing them means protecting those systems while recognising the threats they bring.

• Mount Rainier National Park: engineered log jams protect historic roads along a river from glacial lake outburst floods — sudden releases of water from a melting or shifting glacier or heavy rain — by absorbing the flood's energy, imitating natural log jams without spoiling the scenery or historic character.
• Vanderbilt Mansion National Historic Site: the historic plantings included highly invasive barberry and English ivy, so the treatment plan specifies non-invasive substitutes to keep them from spreading into nearby forests.
• Hawai‘i Volcanoes National Park: endangered nēnē nest on the ground at ‘Āinahou Ranch in winter, so the Park Service schedules mowing and other work around them.
• Golden Gate National Recreation Area: drought-tolerant native plantings keep the historic character and survive the dry summers. Building resilience can mean stronger materials, healthier living systems or hardier species.

The Carbon River Project: installing engineered log jams to protect the Carbon River entrance of Mount Rainier National Park from floods. NPS.

The Hawaiian goose, or nēnē, is found only in Hawai‘i. NPS / David Restivo.

Maintenance, repair and replacement

Routine care matters more as conditions change. Well-kept historic fruit trees, for example, are better able to survive drought and resist disease. The orchards at Eugene O'Neill National Historic Site need regular care and, as they age, occasional replacement.

By 1944 there were about 115 almond trees at what is now Eugene O'Neill National Historic Site; today there are about 83, some 36 of them historic, with replacements planted over the years. NPS.

Moving resources

Sometimes no protection is enough, and a high-value resource is moved out of harm's way. When the Cape Hatteras Light Station was moved in 1999 because of shoreline erosion, other features of the station's landscape moved with it, keeping their 1870 alignment and the layout of the historic buildings. It is not the only cultural resource moved for protection, safety or a changing environment.

Recording and letting go

Some resources cannot be saved. Then the only practical course is to record them and let them go, keeping their stories and lessons alive through cultural practice.

Adaptation can react to change, or anticipate it through planning and action that protect resources before climate impacts arrive.

Sources

• National Park Service, "Climate Change and Cultural Landscapes: Adapt", in Climate Change Response Strategy and Cultural Landscapes. https://www.nps.gov/articles/000/climate-change-response-strategy-cultural-landscapes-adapt.htm — its Carbon River Project film (5 minutes, 33 seconds) recovered from nps.gov.
• Rewritten in hubnx's own words.