[Campbell Biology P.822] Based on the "Ring-width indexes" graph in Figure 35.21 for Mongoli... | Practice Question

Based on the "Ring-width indexes" graph in Figure 35.21 for Mongolian conifers from 1550 to 1993, which of the following statements is the most accurate interpretation regarding the region's climate?

  • A: The climate remained consistently warm throughout the entire period, with minor fluctuations.
  • B: There was a general warming trend from approximately the mid-19th century towards the late 20th century.
  • C: The coldest period occurred around the early 1600s, followed by continuous warming until 1993.
  • D: Ring-width indexes show no correlation with temperature changes, as indicated by the irregular fluctuations.

Explanation

The graph shows clear fluctuations in ring-width indexes, which correlate with temperature. Observing the trend from around 1850-1900 onwards, there is a noticeable general increase in the ring-width index, suggesting a warming trend towards the end of the studied period, consistent with the description of dendrochronology being used to study climate change, including recent global warming.