3342
This species - specific mixing of new with old C pools is likely to mask year - or season - specific linkages between tree ring formation and climate and has considerable implications for climate reconstruction using stable isotopes as proxies for past climatic conditions .
 tree ring
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 tree ring