Question

use the information below to answer the question. predicted number of new saguaro plants. scientists studied 6 populations of saguaro cactus plants. the graph shows the average predicted number of new saguaro cactus plants over time. a saguaro cactus does not flower until it is at least 30 years old. each plant can live up to 250 years. in the first few years of a saguaros life, the plant requires stable conditions. it grows under another tree for protection. which statement provides the best explanation for the predicted trend shown in the graph? 1. climate change will cause an increase in heat - stress on the saguaros. 2. saguaros will flower more quickly, which will increase their reproductive success. 3. saguaros will experience a decrease in competition, which will increase their reproductive success. 4. climate change will increase the availability of native trees that are used by the saguaros for protection.

Explanation:

The graph shows a decline in the predicted number of new saguaro cactus plants over time. Saguaros need stable conditions and grow under other trees for protection. Climate - change - induced heat stress can negatively impact their growth and survival, which is consistent with the downward trend in the graph. Other options like increased flowering, decreased competition, or increased availability of nurse trees would likely lead to an increase in the number of new plants, not a decrease.

Answer:

A. Climate change will cause an increase in heat stress on the saguaros.