Where do cool conditions often shift as climate warms?

• Toward lower latitudes or elevations
• Toward higher latitudes or elevations
• Toward warmer lowland habitats near the equator

Which record measures plant phenology?

• Flowering date each spring
• Flower mass at peak bloom
• Root depth below the soil

In a hypothetical season, insects peak on day 20 and chicks hatch on day 28. Both days use the same starting date. How many days after the insect peak do the chicks hatch?

A coral loses symbiotic algae during heat stress and turns pale. Which conclusion is justified?

• The coral is bleached but might recover
• The reef has shifted to a persistent new state
• The coral has died from overheating

Insects peak earlier, but chicks hatch at their old time. Why can chick survival decline?

• Chicks may need less food as insects emerge earlier
• Earlier insects may improve food overlap
• Chicks may hatch after the insect food peak

Suitable habitat for a plant shifts beyond a barrier. Its seeds rarely cross it. Which limitation on range movement is directly described?

• Seeds reach the site but fail to germinate
• Seed dispersal limits arrival in new suitable habitat
• Seed production declines as the plant adapts to the warmer conditions

Stress increases gradually. An ecosystem changes little at first, then changes rapidly after a small further increase in stress. Which mechanism best explains this pattern?

• The pressure reverses before the ecosystem responds
• The ecosystem response accumulates at a steady rate
• A threshold separates limited response from rapid change

Heat eases after kelp loss, but surviving urchins keep eating new kelp. Which continuing process described here can hinder forest recovery?

• The heat event may have exhausted stored nutrients
• Continued grazing can maintain a low-kelp state
• Cool water may slow kelp growth