• Snowpack timing is shifting earlier; spring melt now arrives 1-4 weeks before mid-20th-century baseline, compressing the high-elevation growing season's water budget.
• Multi-year severe drought + warming winters + fire suppression compound: the 2020-2021 fires killed substantial fractions of named giant sequoia groves, a previously unprecedented mortality.
• Garden-relevant: foothill and mid-elevation Sierra natives (ceanothus, manzanita, fremontodendron) are well-positioned for warmer summers; high-elevation natives (subalpine pines, alpine forbs) face habitat-island contraction.