The Sequoia Ecosystem

• Giant Forest Restoration Overview
• Before and After Photos
• Mature Sequoias
• The Visitor Experience
• History of Development

Development had extensive impacts on the overall giant sequoia ecosystem - soil, water, vegetation, animals, and processes that shaped the forest.

One such process is fire. It is a natural process that has shaped giant sequoia forests for millennia. Due to the presence of buildings, the park prevented fire from burning in and around the developed area. Yet without fire, giant sequoia seedlings fail to germinate. With no young sequoias to replace them, the towering sequoias in the Village area would be the last to stand there. Learn more about the Sequoia and Kings Canyon National Parks fire and fuels management program.

Modification of landforms caused water runoff from rainstorms and snowmelt to concentrate and form gullies, increasing soil erosion. Landforms had been modified in several ways: (1) creating level pads for buildings and parking lots, (2) cutting into slopes and side-casting this material to construct road benches, and (3) filling over wetland and stream areas.

 

Workers labor to re-line a drainage culvert in the Giant Forest

NPS Photo

Wetland and stream habitats may have been affected by leaking sewage where aging sewer lines ran alongside or across streams. Runoff from parking lots and the gas station likely contained petroleum residues, which may have altered wetland and stream habitats. Soils had become more compact, eroded, depleted of organic matter, and altered from natural crumb and granular structures. The natural litter and duff layer was absent from the forest floor. These impacts likely reduced the ability of surface soils to hold water and nutrients and maintain the aeration necessary for root health. Organically rich topsoil is a precious resource; its loss or degradation can have serious long-term consequences for ecosystem health.

The structure of the vegetation had been altered. The mature forest overstory was less dense than that of the surrounding forest (see footnote below) because trees that threatened human safety and property were removed. Trees were also cleared for buildings and parking lots, creating distinct openings in the forest overstory. The forest floor was barren because soil compaction and foot trampling reduced germination and growth of the forest understory (grasses, wildflowers, shrubs, and tree seedlings). The diminished forest understory produced fewer inputs of seed to the soil. With less seed stored in this "soil seed bank," the regenerative potential of the forest was reduced. In the extreme case, widespread covering of soil surfaces by asphalt completely prevented seed inputs.

Footnote: However, the lower density forest seen in the Giant Forest Village today may be similar to the forests that existed prior to the arrival of Euro-Americans, who suppressed fires that would naturally thin out dense stands of young trees. Early visitors to the sequoia groves described an open, "park-like" forest structure. Among other changes, today’s forests that have not sustained fire for nearly a century are more closed, with higher densities of white fir trees that are able to reproduce in shade.